diff --git a/packages/camera/camera_android/example/android/build.gradle b/packages/camera/camera_android/example/android/build.gradle
index c21bff8e0a2f..e54be495b413 100644
--- a/packages/camera/camera_android/example/android/build.gradle
+++ b/packages/camera/camera_android/example/android/build.gradle
@@ -27,3 +27,17 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":camera_android") {
+        tasks.withType(JavaCompile) {
+            // TODO(stuartmorgan): Enable this. See
+            // https://github.com/flutter/flutter/issues/91868
+            //options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/camera/camera_android_camerax/android/src/main/java/io/flutter/plugins/camerax/ProcessCameraProviderHostApiImpl.java b/packages/camera/camera_android_camerax/android/src/main/java/io/flutter/plugins/camerax/ProcessCameraProviderHostApiImpl.java
index e7036e7090c1..b8c91a8c1ae1 100644
--- a/packages/camera/camera_android_camerax/android/src/main/java/io/flutter/plugins/camerax/ProcessCameraProviderHostApiImpl.java
+++ b/packages/camera/camera_android_camerax/android/src/main/java/io/flutter/plugins/camerax/ProcessCameraProviderHostApiImpl.java
@@ -120,9 +120,7 @@ public Long bindToLifecycle(
                   instanceManager.getInstance(((Number) useCaseIds.get(i)).longValue()));
     }
 
-    Camera camera =
-        processCameraProvider.bindToLifecycle(
-            (LifecycleOwner) lifecycleOwner, cameraSelector, useCases);
+    Camera camera = processCameraProvider.bindToLifecycle(lifecycleOwner, cameraSelector, useCases);
 
     final CameraFlutterApiImpl cameraFlutterApi =
         new CameraFlutterApiImpl(binaryMessenger, instanceManager);
diff --git a/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/PreviewTest.java b/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/PreviewTest.java
index 9cb4e910dbb8..b76a4c91842e 100644
--- a/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/PreviewTest.java
+++ b/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/PreviewTest.java
@@ -30,6 +30,7 @@
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.mockito.ArgumentCaptor;
+import org.mockito.ArgumentMatchers;
 import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnit;
 import org.mockito.junit.MockitoRule;
@@ -107,7 +108,6 @@ public void setSurfaceProviderTest_createsSurfaceProviderAndReturnsTextureEntryI
     final ArgumentCaptor<Preview.SurfaceProvider> surfaceProviderCaptor =
         ArgumentCaptor.forClass(Preview.SurfaceProvider.class);
     final ArgumentCaptor<Surface> surfaceCaptor = ArgumentCaptor.forClass(Surface.class);
-    final ArgumentCaptor<Consumer> consumerCaptor = ArgumentCaptor.forClass(Consumer.class);
 
     // Test that surface provider was set and the surface texture ID was returned.
     assertEquals(previewHostApi.setSurfaceProvider(previewIdentifier), surfaceTextureEntryId);
@@ -136,7 +136,9 @@ public void createSurfaceProvider_createsExpectedPreviewSurfaceProvider() {
         .thenReturn(mockSystemServicesFlutterApi);
 
     final ArgumentCaptor<Surface> surfaceCaptor = ArgumentCaptor.forClass(Surface.class);
-    final ArgumentCaptor<Consumer> consumerCaptor = ArgumentCaptor.forClass(Consumer.class);
+    @SuppressWarnings("unchecked")
+    final ArgumentCaptor<Consumer<SurfaceRequest.Result>> consumerCaptor =
+        ArgumentCaptor.forClass(Consumer.class);
 
     Preview.SurfaceProvider previewSurfaceProvider =
         previewHostApi.createSurfaceProvider(mockSurfaceTexture);
@@ -183,7 +185,8 @@ public void createSurfaceProvider_createsExpectedPreviewSurfaceProvider() {
         .thenReturn(SurfaceRequest.Result.RESULT_INVALID_SURFACE);
     capturedConsumer.accept(mockSurfaceRequestResult);
     verify(mockSurface).release();
-    verify(mockSystemServicesFlutterApi).sendCameraError(anyString(), any(Reply.class));
+    verify(mockSystemServicesFlutterApi)
+        .sendCameraError(anyString(), ArgumentMatchers.<Reply<Void>>any());
   }
 
   @Test
diff --git a/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/ProcessCameraProviderTest.java b/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/ProcessCameraProviderTest.java
index 47b4ed6ad26d..7efd4576c208 100644
--- a/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/ProcessCameraProviderTest.java
+++ b/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/ProcessCameraProviderTest.java
@@ -66,6 +66,7 @@ public void getInstanceTest() {
         new ProcessCameraProviderHostApiImpl(mockBinaryMessenger, testInstanceManager, context);
     final ListenableFuture<ProcessCameraProvider> processCameraProviderFuture =
         spy(Futures.immediateFuture(processCameraProvider));
+    @SuppressWarnings("unchecked")
     final GeneratedCameraXLibrary.Result<Long> mockResult =
         mock(GeneratedCameraXLibrary.Result.class);
 
diff --git a/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/SystemServicesTest.java b/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/SystemServicesTest.java
index eb36c452ec3b..562fbe8b526d 100644
--- a/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/SystemServicesTest.java
+++ b/packages/camera/camera_android_camerax/android/src/test/java/io/flutter/plugins/camerax/SystemServicesTest.java
@@ -24,6 +24,7 @@
 import org.junit.Rule;
 import org.junit.Test;
 import org.mockito.ArgumentCaptor;
+import org.mockito.ArgumentMatchers;
 import org.mockito.Mock;
 import org.mockito.junit.MockitoJUnit;
 import org.mockito.junit.MockitoRule;
@@ -43,6 +44,7 @@ public void requestCameraPermissionsTest() {
         mock(CameraPermissionsManager.class);
     final Activity mockActivity = mock(Activity.class);
     final PermissionsRegistry mockPermissionsRegistry = mock(PermissionsRegistry.class);
+    @SuppressWarnings("unchecked")
     final Result<CameraPermissionsErrorData> mockResult = mock(Result.class);
     final Boolean enableAudio = false;
 
@@ -65,7 +67,7 @@ public void requestCameraPermissionsTest() {
             eq(enableAudio),
             resultCallbackCaptor.capture());
 
-    ResultCallback resultCallback = (ResultCallback) resultCallbackCaptor.getValue();
+    ResultCallback resultCallback = resultCallbackCaptor.getValue();
 
     // Test no error data is sent upon permissions request success.
     resultCallback.onResult(null, null);
@@ -130,7 +132,7 @@ public void deviceOrientationChangeTest() {
     deviceOrientationChangeCallback.onChange(DeviceOrientation.PORTRAIT_DOWN);
     verify(systemServicesFlutterApi)
         .sendDeviceOrientationChangedEvent(
-            eq(DeviceOrientation.PORTRAIT_DOWN.toString()), any(Reply.class));
+            eq(DeviceOrientation.PORTRAIT_DOWN.toString()), ArgumentMatchers.<Reply<Void>>any());
 
     // Test that the DeviceOrientationManager starts listening for device orientation changes.
     verify(mockDeviceOrientationManager).start();
diff --git a/packages/camera/camera_android_camerax/example/android/build.gradle b/packages/camera/camera_android_camerax/example/android/build.gradle
index 8640e4de86a1..7c909c6116c0 100644
--- a/packages/camera/camera_android_camerax/example/android/build.gradle
+++ b/packages/camera/camera_android_camerax/example/android/build.gradle
@@ -29,3 +29,15 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":camera_android_camerax") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/espresso/example/android/build.gradle b/packages/espresso/example/android/build.gradle
index c21bff8e0a2f..10fc8d91f5f1 100644
--- a/packages/espresso/example/android/build.gradle
+++ b/packages/espresso/example/android/build.gradle
@@ -27,3 +27,17 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":espresso") {
+        tasks.withType(JavaCompile) {
+            // TODO(stuartmorgan): Enable this. See
+            // https://github.com/flutter/flutter/issues/91868
+            //options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/flutter_plugin_android_lifecycle/android/src/test/java/io/flutter/embedding/engine/plugins/lifecycle/FlutterLifecycleAdapterTest.java b/packages/flutter_plugin_android_lifecycle/android/src/test/java/io/flutter/embedding/engine/plugins/lifecycle/FlutterLifecycleAdapterTest.java
index 08bb3d7266e8..9a6bfb7da5ba 100644
--- a/packages/flutter_plugin_android_lifecycle/android/src/test/java/io/flutter/embedding/engine/plugins/lifecycle/FlutterLifecycleAdapterTest.java
+++ b/packages/flutter_plugin_android_lifecycle/android/src/test/java/io/flutter/embedding/engine/plugins/lifecycle/FlutterLifecycleAdapterTest.java
@@ -11,6 +11,7 @@
 import androidx.lifecycle.Lifecycle;
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
 import io.flutter.plugin.common.PluginRegistry;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mock;
@@ -19,9 +20,16 @@
 public class FlutterLifecycleAdapterTest {
   @Mock Lifecycle lifecycle;
 
+  AutoCloseable mockCloseable;
+
   @Before
   public void setUp() {
-    MockitoAnnotations.initMocks(this);
+    mockCloseable = MockitoAnnotations.openMocks(this);
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    mockCloseable.close();
   }
 
   @Test
diff --git a/packages/flutter_plugin_android_lifecycle/example/android/build.gradle b/packages/flutter_plugin_android_lifecycle/example/android/build.gradle
index c21bff8e0a2f..8b3d2202775d 100644
--- a/packages/flutter_plugin_android_lifecycle/example/android/build.gradle
+++ b/packages/flutter_plugin_android_lifecycle/example/android/build.gradle
@@ -27,3 +27,15 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":flutter_plugin_android_lifecycle") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/google_maps_flutter/google_maps_flutter_android/CHANGELOG.md b/packages/google_maps_flutter/google_maps_flutter_android/CHANGELOG.md
index fc0771d214fb..0607df422e83 100644
--- a/packages/google_maps_flutter/google_maps_flutter_android/CHANGELOG.md
+++ b/packages/google_maps_flutter/google_maps_flutter_android/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 2.4.8
+
+* Fixes compilation warnings.
+
 ## 2.4.7
 
 * Updates annotation dependency.
diff --git a/packages/google_maps_flutter/google_maps_flutter_android/android/src/main/java/io/flutter/plugins/googlemaps/Convert.java b/packages/google_maps_flutter/google_maps_flutter_android/android/src/main/java/io/flutter/plugins/googlemaps/Convert.java
index 22c8f4d24be6..78c7dc2428c6 100644
--- a/packages/google_maps_flutter/google_maps_flutter_android/android/src/main/java/io/flutter/plugins/googlemaps/Convert.java
+++ b/packages/google_maps_flutter/google_maps_flutter_android/android/src/main/java/io/flutter/plugins/googlemaps/Convert.java
@@ -25,7 +25,6 @@
 import com.google.android.gms.maps.model.RoundCap;
 import com.google.android.gms.maps.model.SquareCap;
 import com.google.android.gms.maps.model.Tile;
-import io.flutter.view.FlutterMain;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.HashMap;
@@ -50,15 +49,16 @@ private static BitmapDescriptor toBitmapDescriptor(Object o) {
       case "fromAsset":
         if (data.size() == 2) {
           return BitmapDescriptorFactory.fromAsset(
-              FlutterMain.getLookupKeyForAsset(toString(data.get(1))));
+              io.flutter.view.FlutterMain.getLookupKeyForAsset(toString(data.get(1))));
         } else {
           return BitmapDescriptorFactory.fromAsset(
-              FlutterMain.getLookupKeyForAsset(toString(data.get(1)), toString(data.get(2))));
+              io.flutter.view.FlutterMain.getLookupKeyForAsset(
+                  toString(data.get(1)), toString(data.get(2))));
         }
       case "fromAssetImage":
         if (data.size() == 3) {
           return BitmapDescriptorFactory.fromAsset(
-              FlutterMain.getLookupKeyForAsset(toString(data.get(1))));
+              io.flutter.view.FlutterMain.getLookupKeyForAsset(toString(data.get(1))));
         } else {
           throw new IllegalArgumentException(
               "'fromAssetImage' Expected exactly 3 arguments, got: " + data.size());
diff --git a/packages/google_maps_flutter/google_maps_flutter_android/example/android/build.gradle b/packages/google_maps_flutter/google_maps_flutter_android/example/android/build.gradle
index c21bff8e0a2f..538fd31e3eb1 100644
--- a/packages/google_maps_flutter/google_maps_flutter_android/example/android/build.gradle
+++ b/packages/google_maps_flutter/google_maps_flutter_android/example/android/build.gradle
@@ -27,3 +27,17 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":google_maps_flutter_android") {
+        tasks.withType(JavaCompile) {
+            // TODO(stuartmorgan): Enable this. See
+            // https://github.com/flutter/flutter/issues/91868
+            //options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/google_maps_flutter/google_maps_flutter_android/pubspec.yaml b/packages/google_maps_flutter/google_maps_flutter_android/pubspec.yaml
index 44feff58e34f..2e02e0253b72 100644
--- a/packages/google_maps_flutter/google_maps_flutter_android/pubspec.yaml
+++ b/packages/google_maps_flutter/google_maps_flutter_android/pubspec.yaml
@@ -2,7 +2,7 @@ name: google_maps_flutter_android
 description: Android implementation of the google_maps_flutter plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/google_maps_flutter/google_maps_flutter_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+maps%22
-version: 2.4.7
+version: 2.4.8
 
 environment:
   sdk: ">=2.14.0 <3.0.0"
diff --git a/packages/google_sign_in/google_sign_in_android/android/src/test/java/io/flutter/plugins/googlesignin/GoogleSignInTest.java b/packages/google_sign_in/google_sign_in_android/android/src/test/java/io/flutter/plugins/googlesignin/GoogleSignInTest.java
index 78568460c9e6..cbd2e40c433f 100644
--- a/packages/google_sign_in/google_sign_in_android/android/src/test/java/io/flutter/plugins/googlesignin/GoogleSignInTest.java
+++ b/packages/google_sign_in/google_sign_in_android/android/src/test/java/io/flutter/plugins/googlesignin/GoogleSignInTest.java
@@ -29,6 +29,7 @@
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
+import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
@@ -41,18 +42,23 @@ public class GoogleSignInTest {
   @Mock Context mockContext;
   @Mock Resources mockResources;
   @Mock Activity mockActivity;
-  @Mock PluginRegistry.Registrar mockRegistrar;
   @Mock BinaryMessenger mockMessenger;
   @Spy MethodChannel.Result result;
   @Mock GoogleSignInWrapper mockGoogleSignIn;
   @Mock GoogleSignInAccount account;
   @Mock GoogleSignInClient mockClient;
   @Mock Task<GoogleSignInAccount> mockSignInTask;
+
+  @SuppressWarnings("deprecation")
+  @Mock
+  PluginRegistry.Registrar mockRegistrar;
+
   private GoogleSignInPlugin plugin;
+  private AutoCloseable mockCloseable;
 
   @Before
   public void setUp() {
-    MockitoAnnotations.initMocks(this);
+    mockCloseable = MockitoAnnotations.openMocks(this);
     when(mockRegistrar.messenger()).thenReturn(mockMessenger);
     when(mockRegistrar.context()).thenReturn(mockContext);
     when(mockRegistrar.activity()).thenReturn(mockActivity);
@@ -62,6 +68,11 @@ public void setUp() {
     plugin.setUpRegistrar(mockRegistrar);
   }
 
+  @After
+  public void tearDown() throws Exception {
+    mockCloseable.close();
+  }
+
   @Test
   public void requestScopes_ResultErrorIfAccountIsNull() {
     MethodCall methodCall = new MethodCall("requestScopes", null);
diff --git a/packages/google_sign_in/google_sign_in_android/example/android/build.gradle b/packages/google_sign_in/google_sign_in_android/example/android/build.gradle
index c21bff8e0a2f..c10d0fa94851 100644
--- a/packages/google_sign_in/google_sign_in_android/example/android/build.gradle
+++ b/packages/google_sign_in/google_sign_in_android/example/android/build.gradle
@@ -27,3 +27,15 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":google_sign_in_android") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/image_picker/image_picker_android/CHANGELOG.md b/packages/image_picker/image_picker_android/CHANGELOG.md
index 3b85783c81b2..03935b9b47ec 100644
--- a/packages/image_picker/image_picker_android/CHANGELOG.md
+++ b/packages/image_picker/image_picker_android/CHANGELOG.md
@@ -1,5 +1,6 @@
-## NEXT
+## 0.8.5+9
 
+* Fixes compilation warnings.
 * Updates compileSdkVersion to 33.
 
 ## 0.8.5+8
diff --git a/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerDelegate.java b/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerDelegate.java
index b95fc69ff6b3..006eb3dad47a 100644
--- a/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerDelegate.java
+++ b/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerDelegate.java
@@ -31,12 +31,6 @@
 import java.util.Map;
 import java.util.UUID;
 
-enum CameraDevice {
-  REAR,
-
-  FRONT
-}
-
 /**
  * A delegate class doing the heavy lifting for the plugin.
  *
@@ -86,6 +80,11 @@ public class ImagePickerDelegate
   @VisibleForTesting static final int REQUEST_CODE_TAKE_VIDEO_WITH_CAMERA = 2353;
   @VisibleForTesting static final int REQUEST_CAMERA_VIDEO_PERMISSION = 2355;
 
+  public enum CameraDevice {
+    REAR,
+    FRONT
+  }
+
   @VisibleForTesting final String fileProviderName;
 
   private final Activity activity;
@@ -222,21 +221,22 @@ void saveStateBeforeResult() {
   void retrieveLostImage(MethodChannel.Result result) {
     Map<String, Object> resultMap = cache.getCacheMap();
     @SuppressWarnings("unchecked")
-    ArrayList<String> pathList = (ArrayList<String>) resultMap.get(cache.MAP_KEY_PATH_LIST);
+    ArrayList<String> pathList =
+        (ArrayList<String>) resultMap.get(ImagePickerCache.MAP_KEY_PATH_LIST);
     ArrayList<String> newPathList = new ArrayList<>();
     if (pathList != null) {
       for (String path : pathList) {
-        Double maxWidth = (Double) resultMap.get(cache.MAP_KEY_MAX_WIDTH);
-        Double maxHeight = (Double) resultMap.get(cache.MAP_KEY_MAX_HEIGHT);
+        Double maxWidth = (Double) resultMap.get(ImagePickerCache.MAP_KEY_MAX_WIDTH);
+        Double maxHeight = (Double) resultMap.get(ImagePickerCache.MAP_KEY_MAX_HEIGHT);
         int imageQuality =
-            resultMap.get(cache.MAP_KEY_IMAGE_QUALITY) == null
+            resultMap.get(ImagePickerCache.MAP_KEY_IMAGE_QUALITY) == null
                 ? 100
-                : (int) resultMap.get(cache.MAP_KEY_IMAGE_QUALITY);
+                : (int) resultMap.get(ImagePickerCache.MAP_KEY_IMAGE_QUALITY);
 
         newPathList.add(imageResizer.resizeImageIfNeeded(path, maxWidth, maxHeight, imageQuality));
       }
-      resultMap.put(cache.MAP_KEY_PATH_LIST, newPathList);
-      resultMap.put(cache.MAP_KEY_PATH, newPathList.get(newPathList.size() - 1));
+      resultMap.put(ImagePickerCache.MAP_KEY_PATH_LIST, newPathList);
+      resultMap.put(ImagePickerCache.MAP_KEY_PATH, newPathList.get(newPathList.size() - 1));
     }
     if (resultMap.isEmpty()) {
       result.success(null);
@@ -450,6 +450,8 @@ private File createTemporaryWritableFile(String suffix) {
 
   private void grantUriPermissions(Intent intent, Uri imageUri) {
     PackageManager packageManager = activity.getPackageManager();
+    // TODO(stuartmorgan): Add new codepath: https://github.com/flutter/flutter/issues/121816
+    @SuppressWarnings("deprecation")
     List<ResolveInfo> compatibleActivities =
         packageManager.queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
 
diff --git a/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerPlugin.java b/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerPlugin.java
index 8336a145e93a..a1ee1e2f404e 100644
--- a/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerPlugin.java
+++ b/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerPlugin.java
@@ -342,12 +342,12 @@ public void onMethodCall(MethodCall call, MethodChannel.Result rawResult) {
     int imageSource;
     ImagePickerDelegate delegate = activityState.getDelegate();
     if (call.argument("cameraDevice") != null) {
-      CameraDevice device;
+      ImagePickerDelegate.CameraDevice device;
       int deviceIntValue = call.argument("cameraDevice");
       if (deviceIntValue == CAMERA_DEVICE_FRONT) {
-        device = CameraDevice.FRONT;
+        device = ImagePickerDelegate.CameraDevice.FRONT;
       } else {
-        device = CameraDevice.REAR;
+        device = ImagePickerDelegate.CameraDevice.REAR;
       }
       delegate.setCameraDevice(device);
     }
diff --git a/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerUtils.java b/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerUtils.java
index ba9878925575..5e80258a00d5 100644
--- a/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerUtils.java
+++ b/packages/image_picker/image_picker_android/android/src/main/java/io/flutter/plugins/imagepicker/ImagePickerUtils.java
@@ -16,6 +16,8 @@ final class ImagePickerUtils {
   private static boolean isPermissionPresentInManifest(Context context, String permissionName) {
     try {
       PackageManager packageManager = context.getPackageManager();
+      // TODO(stuartmorgan): Add new codepath: https://github.com/flutter/flutter/issues/121816
+      @SuppressWarnings("deprecation")
       PackageInfo packageInfo =
           packageManager.getPackageInfo(context.getPackageName(), PackageManager.GET_PERMISSIONS);
 
diff --git a/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerCacheTest.java b/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerCacheTest.java
index 92070e7a65c5..7d8716659784 100644
--- a/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerCacheTest.java
+++ b/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerCacheTest.java
@@ -6,8 +6,8 @@
 
 import static io.flutter.plugins.imagepicker.ImagePickerCache.MAP_KEY_IMAGE_QUALITY;
 import static io.flutter.plugins.imagepicker.ImagePickerCache.SHARED_PREFERENCES_NAME;
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.IsEqual.equalTo;
-import static org.junit.Assert.assertThat;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
@@ -19,6 +19,7 @@
 import io.flutter.plugin.common.MethodCall;
 import java.util.HashMap;
 import java.util.Map;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.mockito.Mock;
@@ -34,11 +35,13 @@ public class ImagePickerCacheTest {
 
   static Map<String, Object> preferenceStorage;
 
+  AutoCloseable mockCloseable;
+
   @Before
   public void setUp() {
-    MockitoAnnotations.initMocks(this);
+    mockCloseable = MockitoAnnotations.openMocks(this);
 
-    preferenceStorage = new HashMap();
+    preferenceStorage = new HashMap<String, Object>();
     when(mockActivity.getPackageName()).thenReturn("com.example.test");
     when(mockActivity.getPackageManager()).thenReturn(mock(PackageManager.class));
     when(mockActivity.getSharedPreferences(SHARED_PREFERENCES_NAME, Context.MODE_PRIVATE))
@@ -97,19 +100,25 @@ public void setUp() {
     when(mockPreference.contains(any(String.class))).thenReturn(true);
   }
 
+  @After
+  public void tearDown() throws Exception {
+    mockCloseable.close();
+  }
+
   @Test
   public void ImageCache_ShouldBeAbleToSetAndGetQuality() {
     when(mockMethodCall.argument(MAP_KEY_IMAGE_QUALITY)).thenReturn(IMAGE_QUALITY);
     ImagePickerCache cache = new ImagePickerCache(mockActivity);
     cache.saveDimensionWithMethodCall(mockMethodCall);
     Map<String, Object> resultMap = cache.getCacheMap();
-    int imageQuality = (int) resultMap.get(cache.MAP_KEY_IMAGE_QUALITY);
+    int imageQuality = (int) resultMap.get(ImagePickerCache.MAP_KEY_IMAGE_QUALITY);
     assertThat(imageQuality, equalTo(IMAGE_QUALITY));
 
     when(mockMethodCall.argument(MAP_KEY_IMAGE_QUALITY)).thenReturn(null);
     cache.saveDimensionWithMethodCall(mockMethodCall);
     Map<String, Object> resultMapWithDefaultQuality = cache.getCacheMap();
-    int defaultImageQuality = (int) resultMapWithDefaultQuality.get(cache.MAP_KEY_IMAGE_QUALITY);
+    int defaultImageQuality =
+        (int) resultMapWithDefaultQuality.get(ImagePickerCache.MAP_KEY_IMAGE_QUALITY);
     assertThat(defaultImageQuality, equalTo(100));
   }
 }
diff --git a/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerDelegateTest.java b/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerDelegateTest.java
index 3a6fd0c48c01..29302d90bffd 100644
--- a/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerDelegateTest.java
+++ b/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerDelegateTest.java
@@ -4,9 +4,9 @@
 
 package io.flutter.plugins.imagepicker;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.IsEqual.equalTo;
 import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertThat;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.anyInt;
 import static org.mockito.ArgumentMatchers.eq;
@@ -63,6 +63,8 @@ public class ImagePickerDelegateTest {
   ImagePickerDelegate.FileUriResolver mockFileUriResolver;
   MockedStatic<File> mockStaticFile;
 
+  AutoCloseable mockCloseable;
+
   private static class MockFileUriResolver implements ImagePickerDelegate.FileUriResolver {
     @Override
     public Uri resolveFileProviderUriForFile(String fileProviderName, File imageFile) {
@@ -77,7 +79,7 @@ public void getFullImagePath(Uri imageUri, ImagePickerDelegate.OnPathReadyListen
 
   @Before
   public void setUp() {
-    MockitoAnnotations.initMocks(this);
+    mockCloseable = MockitoAnnotations.openMocks(this);
 
     mockStaticFile = Mockito.mockStatic(File.class);
     mockStaticFile
@@ -108,8 +110,9 @@ public void setUp() {
   }
 
   @After
-  public void tearDown() {
+  public void tearDown() throws Exception {
     mockStaticFile.close();
+    mockCloseable.close();
   }
 
   @Test
@@ -388,6 +391,7 @@ public void onActivityResult_WhenImagePickedFromGallery_AndNoResizeNeeded_Stores
     delegate.onActivityResult(
         ImagePickerDelegate.REQUEST_CODE_CHOOSE_IMAGE_FROM_GALLERY, Activity.RESULT_OK, mockIntent);
 
+    @SuppressWarnings("unchecked")
     ArgumentCaptor<ArrayList<String>> pathListCapture = ArgumentCaptor.forClass(ArrayList.class);
     verify(cache, times(1)).saveResult(pathListCapture.capture(), any(), any());
     assertEquals("pathFromUri", pathListCapture.getValue().get(0));
@@ -503,6 +507,7 @@ public void onActivityResult_WhenImageTakenWithCamera_AndNoResizeNeeded_Finishes
 
     ImagePickerDelegate mockDelegate = createDelegate();
 
+    @SuppressWarnings("unchecked")
     ArgumentCaptor<Map<String, Object>> valueCapture = ArgumentCaptor.forClass(Map.class);
 
     doNothing().when(mockResult).success(valueCapture.capture());
diff --git a/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerPluginTest.java b/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerPluginTest.java
index 36452479776e..328c964c860c 100644
--- a/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerPluginTest.java
+++ b/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImagePickerPluginTest.java
@@ -4,10 +4,12 @@
 
 package io.flutter.plugins.imagepicker;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.IsEqual.equalTo;
+import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertThrows;
 import static org.junit.Assert.assertTrue;
 import static org.mockito.ArgumentMatchers.any;
 import static org.mockito.ArgumentMatchers.eq;
@@ -29,10 +31,9 @@
 import java.io.File;
 import java.util.HashMap;
 import java.util.Map;
+import org.junit.After;
 import org.junit.Before;
-import org.junit.Rule;
 import org.junit.Test;
-import org.junit.rules.ExpectedException;
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
@@ -43,8 +44,6 @@ public class ImagePickerPluginTest {
   private static final String PICK_MULTI_IMAGE = "pickMultiImage";
   private static final String PICK_VIDEO = "pickVideo";
 
-  @Rule public ExpectedException exception = ExpectedException.none();
-
   @SuppressWarnings("deprecation")
   @Mock
   io.flutter.plugin.common.PluginRegistry.Registrar mockRegistrar;
@@ -59,15 +58,22 @@ public class ImagePickerPluginTest {
 
   ImagePickerPlugin plugin;
 
+  AutoCloseable mockCloseable;
+
   @Before
   public void setUp() {
-    MockitoAnnotations.initMocks(this);
+    mockCloseable = MockitoAnnotations.openMocks(this);
     when(mockRegistrar.context()).thenReturn(mockApplication);
     when(mockActivityBinding.getActivity()).thenReturn(mockActivity);
     when(mockPluginBinding.getApplicationContext()).thenReturn(mockApplication);
     plugin = new ImagePickerPlugin(mockImagePickerDelegate, mockActivity);
   }
 
+  @After
+  public void tearDown() throws Exception {
+    mockCloseable.close();
+  }
+
   @Test
   public void onMethodCall_WhenActivityIsNull_FinishesWithForegroundActivityRequiredError() {
     MethodCall call = buildMethodCall(PICK_IMAGE, SOURCE_GALLERY);
@@ -81,18 +87,22 @@ public void onMethodCall_WhenActivityIsNull_FinishesWithForegroundActivityRequir
 
   @Test
   public void onMethodCall_WhenCalledWithUnknownMethod_ThrowsException() {
-    exception.expect(IllegalArgumentException.class);
-    exception.expectMessage("Unknown method test");
-    plugin.onMethodCall(new MethodCall("test", null), mockResult);
+    IllegalArgumentException e =
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> plugin.onMethodCall(new MethodCall("test", null), mockResult));
+    assertEquals(e.getMessage(), "Unknown method test");
     verifyNoInteractions(mockImagePickerDelegate);
     verifyNoInteractions(mockResult);
   }
 
   @Test
   public void onMethodCall_WhenCalledWithUnknownImageSource_ThrowsException() {
-    exception.expect(IllegalArgumentException.class);
-    exception.expectMessage("Invalid image source: -1");
-    plugin.onMethodCall(buildMethodCall(PICK_IMAGE, -1), mockResult);
+    IllegalArgumentException e =
+        assertThrows(
+            IllegalArgumentException.class,
+            () -> plugin.onMethodCall(buildMethodCall(PICK_IMAGE, -1), mockResult));
+    assertEquals(e.getMessage(), "Invalid image source: -1");
     verifyNoInteractions(mockImagePickerDelegate);
     verifyNoInteractions(mockResult);
   }
@@ -124,39 +134,39 @@ public void onMethodCall_WhenSourceIsCamera_InvokesTakeImageWithCamera() {
   @Test
   public void onMethodCall_PickingImage_WhenSourceIsCamera_InvokesTakeImageWithCamera_RearCamera() {
     MethodCall call = buildMethodCall(PICK_IMAGE, SOURCE_CAMERA);
-    HashMap<String, Object> arguments = (HashMap<String, Object>) call.arguments;
+    HashMap<String, Object> arguments = getArgumentMap(call);
     arguments.put("cameraDevice", 0);
     plugin.onMethodCall(call, mockResult);
-    verify(mockImagePickerDelegate).setCameraDevice(eq(CameraDevice.REAR));
+    verify(mockImagePickerDelegate).setCameraDevice(eq(ImagePickerDelegate.CameraDevice.REAR));
   }
 
   @Test
   public void
       onMethodCall_PickingImage_WhenSourceIsCamera_InvokesTakeImageWithCamera_FrontCamera() {
     MethodCall call = buildMethodCall(PICK_IMAGE, SOURCE_CAMERA);
-    HashMap<String, Object> arguments = (HashMap<String, Object>) call.arguments;
+    HashMap<String, Object> arguments = getArgumentMap(call);
     arguments.put("cameraDevice", 1);
     plugin.onMethodCall(call, mockResult);
-    verify(mockImagePickerDelegate).setCameraDevice(eq(CameraDevice.FRONT));
+    verify(mockImagePickerDelegate).setCameraDevice(eq(ImagePickerDelegate.CameraDevice.FRONT));
   }
 
   @Test
   public void onMethodCall_PickingVideo_WhenSourceIsCamera_InvokesTakeImageWithCamera_RearCamera() {
     MethodCall call = buildMethodCall(PICK_IMAGE, SOURCE_CAMERA);
-    HashMap<String, Object> arguments = (HashMap<String, Object>) call.arguments;
+    HashMap<String, Object> arguments = getArgumentMap(call);
     arguments.put("cameraDevice", 0);
     plugin.onMethodCall(call, mockResult);
-    verify(mockImagePickerDelegate).setCameraDevice(eq(CameraDevice.REAR));
+    verify(mockImagePickerDelegate).setCameraDevice(eq(ImagePickerDelegate.CameraDevice.REAR));
   }
 
   @Test
   public void
       onMethodCall_PickingVideo_WhenSourceIsCamera_InvokesTakeImageWithCamera_FrontCamera() {
     MethodCall call = buildMethodCall(PICK_IMAGE, SOURCE_CAMERA);
-    HashMap<String, Object> arguments = (HashMap<String, Object>) call.arguments;
+    HashMap<String, Object> arguments = getArgumentMap(call);
     arguments.put("cameraDevice", 1);
     plugin.onMethodCall(call, mockResult);
-    verify(mockImagePickerDelegate).setCameraDevice(eq(CameraDevice.FRONT));
+    verify(mockImagePickerDelegate).setCameraDevice(eq(ImagePickerDelegate.CameraDevice.FRONT));
   }
 
   @Test
@@ -217,4 +227,9 @@ private MethodCall buildMethodCall(String method, final int source) {
   private MethodCall buildMethodCall(String method) {
     return new MethodCall(method, null);
   }
+
+  @SuppressWarnings("unchecked")
+  private HashMap<String, Object> getArgumentMap(MethodCall call) {
+    return (HashMap<String, Object>) call.arguments;
+  }
 }
diff --git a/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImageResizerTest.java b/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImageResizerTest.java
index 73cfef9e88ea..a3710038379f 100644
--- a/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImageResizerTest.java
+++ b/packages/image_picker/image_picker_android/android/src/test/java/io/flutter/plugins/imagepicker/ImageResizerTest.java
@@ -4,13 +4,14 @@
 
 package io.flutter.plugins.imagepicker;
 
+import static org.hamcrest.MatcherAssert.assertThat;
 import static org.hamcrest.core.IsEqual.equalTo;
-import static org.junit.Assert.assertThat;
 
 import android.graphics.Bitmap;
 import android.graphics.BitmapFactory;
 import java.io.File;
 import java.io.IOException;
+import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -28,9 +29,11 @@ public class ImageResizerTest {
   File externalDirectory;
   Bitmap originalImageBitmap;
 
+  AutoCloseable mockCloseable;
+
   @Before
   public void setUp() throws IOException {
-    MockitoAnnotations.initMocks(this);
+    mockCloseable = MockitoAnnotations.openMocks(this);
     imageFile = new File(getClass().getClassLoader().getResource("pngImage.png").getFile());
     originalImageBitmap = BitmapFactory.decodeFile(imageFile.getPath());
     TemporaryFolder temporaryFolder = new TemporaryFolder();
@@ -39,6 +42,11 @@ public void setUp() throws IOException {
     resizer = new ImageResizer(externalDirectory, new ExifDataCopier());
   }
 
+  @After
+  public void tearDown() throws Exception {
+    mockCloseable.close();
+  }
+
   @Test
   public void onResizeImageIfNeeded_WhenQualityIsNull_ShoultNotResize_ReturnTheUnscaledFile() {
     String outoutFile = resizer.resizeImageIfNeeded(imageFile.getPath(), null, null, null);
diff --git a/packages/image_picker/image_picker_android/example/android/build.gradle b/packages/image_picker/image_picker_android/example/android/build.gradle
index e29a4431f2ae..ac83e8773235 100755
--- a/packages/image_picker/image_picker_android/example/android/build.gradle
+++ b/packages/image_picker/image_picker_android/example/android/build.gradle
@@ -27,3 +27,15 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":image_picker_android") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/image_picker/image_picker_android/pubspec.yaml b/packages/image_picker/image_picker_android/pubspec.yaml
index cd606752e31a..de62db1d86da 100755
--- a/packages/image_picker/image_picker_android/pubspec.yaml
+++ b/packages/image_picker/image_picker_android/pubspec.yaml
@@ -3,7 +3,7 @@ description: Android implementation of the image_picker plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/image_picker/image_picker_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+image_picker%22
 
-version: 0.8.5+8
+version: 0.8.5+9
 
 environment:
   sdk: ">=2.14.0 <3.0.0"
diff --git a/packages/in_app_purchase/in_app_purchase_android/example/android/build.gradle b/packages/in_app_purchase/in_app_purchase_android/example/android/build.gradle
index c21bff8e0a2f..5bb3499d4ff4 100644
--- a/packages/in_app_purchase/in_app_purchase_android/example/android/build.gradle
+++ b/packages/in_app_purchase/in_app_purchase_android/example/android/build.gradle
@@ -27,3 +27,17 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":in_app_purchase_android") {
+        tasks.withType(JavaCompile) {
+            // TODO(stuartmorgan): Enable this. See
+            // https://github.com/flutter/flutter/issues/91868
+            //options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/local_auth/local_auth_android/CHANGELOG.md b/packages/local_auth/local_auth_android/CHANGELOG.md
index b74748c3f2e9..bf94a765a780 100644
--- a/packages/local_auth/local_auth_android/CHANGELOG.md
+++ b/packages/local_auth/local_auth_android/CHANGELOG.md
@@ -1,5 +1,6 @@
-## NEXT
+## 1.0.20
 
+* Fixes compilation warnings.
 * Updates compileSdkVersion to 33.
 
 ## 1.0.19
diff --git a/packages/local_auth/local_auth_android/android/src/main/java/io/flutter/plugins/localauth/LocalAuthPlugin.java b/packages/local_auth/local_auth_android/android/src/main/java/io/flutter/plugins/localauth/LocalAuthPlugin.java
index e545df01e7c0..d724b38c0a79 100644
--- a/packages/local_auth/local_auth_android/android/src/main/java/io/flutter/plugins/localauth/LocalAuthPlugin.java
+++ b/packages/local_auth/local_auth_android/android/src/main/java/io/flutter/plugins/localauth/LocalAuthPlugin.java
@@ -26,7 +26,6 @@
 import io.flutter.plugin.common.MethodChannel.MethodCallHandler;
 import io.flutter.plugin.common.MethodChannel.Result;
 import io.flutter.plugin.common.PluginRegistry;
-import io.flutter.plugin.common.PluginRegistry.Registrar;
 import io.flutter.plugins.localauth.AuthenticationHelper.AuthCompletionHandler;
 import java.util.ArrayList;
 import java.util.concurrent.atomic.AtomicBoolean;
@@ -78,7 +77,7 @@ public boolean onActivityResult(int requestCode, int resultCode, Intent data) {
    *     io.flutter.plugin.common.BinaryMessenger}.
    */
   @SuppressWarnings("deprecation")
-  public static void registerWith(Registrar registrar) {
+  public static void registerWith(PluginRegistry.Registrar registrar) {
     final MethodChannel channel = new MethodChannel(registrar.messenger(), CHANNEL_NAME);
     final LocalAuthPlugin plugin = new LocalAuthPlugin();
     plugin.activity = registrar.activity();
diff --git a/packages/local_auth/local_auth_android/android/src/test/java/io/flutter/plugins/localauth/LocalAuthTest.java b/packages/local_auth/local_auth_android/android/src/test/java/io/flutter/plugins/localauth/LocalAuthTest.java
index 7279a3c49af2..38c3908f4e7c 100644
--- a/packages/local_auth/local_auth_android/android/src/test/java/io/flutter/plugins/localauth/LocalAuthTest.java
+++ b/packages/local_auth/local_auth_android/android/src/test/java/io/flutter/plugins/localauth/LocalAuthTest.java
@@ -238,7 +238,7 @@ public void onDetachedFromActivity_ShouldReleaseActivity() {
 
     final FlutterPluginBinding mockPluginBinding = mock(FlutterPluginBinding.class);
     final FlutterEngine mockFlutterEngine = mock(FlutterEngine.class);
-    when(mockPluginBinding.getFlutterEngine()).thenReturn(mockFlutterEngine);
+    mockDeprecatedFlutterEngineGetter(mockPluginBinding, mockFlutterEngine);
 
     DartExecutor mockDartExecutor = mock(DartExecutor.class);
     when(mockFlutterEngine.getDartExecutor()).thenReturn(mockDartExecutor);
@@ -399,11 +399,17 @@ private void setPluginActivity(LocalAuthPlugin plugin, Activity activity) {
     final ActivityPluginBinding mockActivityBinding = mock(ActivityPluginBinding.class);
     final FlutterEngine mockFlutterEngine = mock(FlutterEngine.class);
     final DartExecutor mockDartExecutor = mock(DartExecutor.class);
-    when(mockPluginBinding.getFlutterEngine()).thenReturn(mockFlutterEngine);
+    mockDeprecatedFlutterEngineGetter(mockPluginBinding, mockFlutterEngine);
     when(mockFlutterEngine.getDartExecutor()).thenReturn(mockDartExecutor);
     when(mockActivityBinding.getActivity()).thenReturn(activity);
     when(mockActivityBinding.getLifecycle()).thenReturn(mockLifecycleReference);
     plugin.onAttachedToEngine(mockPluginBinding);
     plugin.onAttachedToActivity(mockActivityBinding);
   }
+
+  @SuppressWarnings("deprecation")
+  private void mockDeprecatedFlutterEngineGetter(
+      FlutterPluginBinding binding, FlutterEngine engine) {
+    when(binding.getFlutterEngine()).thenReturn(engine);
+  }
 }
diff --git a/packages/local_auth/local_auth_android/example/android/build.gradle b/packages/local_auth/local_auth_android/example/android/build.gradle
index 3593d9636555..9455e41996df 100644
--- a/packages/local_auth/local_auth_android/example/android/build.gradle
+++ b/packages/local_auth/local_auth_android/example/android/build.gradle
@@ -27,3 +27,15 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":local_auth_android") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/local_auth/local_auth_android/pubspec.yaml b/packages/local_auth/local_auth_android/pubspec.yaml
index b668c0e18fb5..e1b9fc8a10e1 100644
--- a/packages/local_auth/local_auth_android/pubspec.yaml
+++ b/packages/local_auth/local_auth_android/pubspec.yaml
@@ -2,7 +2,7 @@ name: local_auth_android
 description: Android implementation of the local_auth plugin.
 repository: https://github.com/flutter/packages/tree/main/packages/local_auth/local_auth_android
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+local_auth%22
-version: 1.0.19
+version: 1.0.20
 
 environment:
   sdk: ">=2.14.0 <3.0.0"
diff --git a/packages/path_provider/path_provider_android/example/android/build.gradle b/packages/path_provider/path_provider_android/example/android/build.gradle
index c21bff8e0a2f..3f8bef9e7b66 100644
--- a/packages/path_provider/path_provider_android/example/android/build.gradle
+++ b/packages/path_provider/path_provider_android/example/android/build.gradle
@@ -27,3 +27,15 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":path_provider_android") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/quick_actions/quick_actions_android/example/android/build.gradle b/packages/quick_actions/quick_actions_android/example/android/build.gradle
index c21bff8e0a2f..4215a59005b9 100644
--- a/packages/quick_actions/quick_actions_android/example/android/build.gradle
+++ b/packages/quick_actions/quick_actions_android/example/android/build.gradle
@@ -27,3 +27,15 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":quick_actions_android") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/shared_preferences/shared_preferences_android/example/android/build.gradle b/packages/shared_preferences/shared_preferences_android/example/android/build.gradle
index 21d50697b9e9..23a5996a120d 100644
--- a/packages/shared_preferences/shared_preferences_android/example/android/build.gradle
+++ b/packages/shared_preferences/shared_preferences_android/example/android/build.gradle
@@ -29,3 +29,15 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":shared_preferences_android") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/url_launcher/url_launcher_android/example/android/build.gradle b/packages/url_launcher/url_launcher_android/example/android/build.gradle
index c21bff8e0a2f..0e9000216693 100644
--- a/packages/url_launcher/url_launcher_android/example/android/build.gradle
+++ b/packages/url_launcher/url_launcher_android/example/android/build.gradle
@@ -27,3 +27,15 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":url_launcher_android") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/video_player/video_player_android/example/android/build.gradle b/packages/video_player/video_player_android/example/android/build.gradle
index c21bff8e0a2f..4851ea6e2c38 100644
--- a/packages/video_player/video_player_android/example/android/build.gradle
+++ b/packages/video_player/video_player_android/example/android/build.gradle
@@ -27,3 +27,17 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":video_player_android") {
+        tasks.withType(JavaCompile) {
+            // TODO(stuartmorgan): Enable this. See
+            // https://github.com/flutter/flutter/issues/91868
+            //options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/packages/webview_flutter/webview_flutter_android/example/android/build.gradle b/packages/webview_flutter/webview_flutter_android/example/android/build.gradle
index e29a4431f2ae..1942e9d40d71 100644
--- a/packages/webview_flutter/webview_flutter_android/example/android/build.gradle
+++ b/packages/webview_flutter/webview_flutter_android/example/android/build.gradle
@@ -27,3 +27,17 @@ subprojects {
 task clean(type: Delete) {
     delete rootProject.buildDir
 }
+
+// Build the plugin project with warnings enabled. This is here rather than
+// in the plugin itself to avoid breaking clients that have different
+// warnings (e.g., deprecation warnings from a newer SDK than this project
+// builds with).
+gradle.projectsEvaluated {
+    project(":webview_flutter_android") {
+        tasks.withType(JavaCompile) {
+            // TODO(stuartmorgan): Enable this. See
+            // https://github.com/flutter/flutter/issues/91868
+            //options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
diff --git a/script/tool/lib/src/lint_android_command.dart b/script/tool/lib/src/lint_android_command.dart
index eb78ce891685..f146b2d4fbbe 100644
--- a/script/tool/lib/src/lint_android_command.dart
+++ b/script/tool/lib/src/lint_android_command.dart
@@ -60,6 +60,38 @@ class LintAndroidCommand extends PackageLoopingCommand {
       if (exitCode != 0) {
         failed = true;
       }
+
+      // In addition to running the Gradle lint step, also ensure that the
+      // example project is configured to build with javac lints enabled and
+      // treated as errors.
+      final List<String> gradleBuildContents = example
+          .platformDirectory(FlutterPlatform.android)
+          .childFile('build.gradle')
+          .readAsLinesSync();
+      // The check here is intentionally somewhat loose, to allow for the
+      // possibility of variations (e.g., not using Xlint:all in some cases, or
+      // passing other arguments).
+      if (!gradleBuildContents.any(
+              (String line) => line.contains('project(":$packageName")')) ||
+          !gradleBuildContents.any((String line) =>
+              line.contains('options.compilerArgs') &&
+              line.contains('-Xlint') &&
+              line.contains('-Werror'))) {
+        failed = true;
+        printError('The example '
+            '${getRelativePosixPath(example.directory, from: package.directory)} '
+            'is not configured to treat javac lints and warnings as errors. '
+            'Please add the following to its build.gradle:');
+        print('''
+gradle.projectsEvaluated {
+    project(":${package.directory.basename}") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
+''');
+      }
     }
 
     return failed ? PackageResult.fail() : PackageResult.success();
diff --git a/script/tool/test/lint_android_command_test.dart b/script/tool/test/lint_android_command_test.dart
index e4a6c5c859e4..40ffaf177a75 100644
--- a/script/tool/test/lint_android_command_test.dart
+++ b/script/tool/test/lint_android_command_test.dart
@@ -39,6 +39,40 @@ void main() {
       runner.addCommand(command);
     });
 
+    void writeFakeBuildGradle(RepositoryPackage example, String pluginName,
+        {bool warningsConfigured = true}) {
+      final String warningConfig = '''
+gradle.projectsEvaluated {
+    project(":$pluginName") {
+        tasks.withType(JavaCompile) {
+            options.compilerArgs << "-Xlint:all" << "-Werror"
+        }
+    }
+}
+''';
+      example
+          .platformDirectory(FlutterPlatform.android)
+          .childFile('build.gradle')
+          .writeAsStringSync('''
+buildscript {
+    repositories {
+        google()
+        mavenCentral()
+    }
+    dependencies {
+        classpath 'com.android.tools.build:gradle:8.0.1'
+    }
+}
+allprojects {
+    repositories {
+        google()
+        mavenCentral()
+    }
+}
+${warningsConfigured ? warningConfig : ''}
+''');
+    }
+
     test('runs gradle lint', () async {
       final RepositoryPackage plugin =
           createFakePlugin('plugin1', packagesDir, extraFiles: <String>[
@@ -46,6 +80,7 @@ void main() {
       ], platformSupport: <String, PlatformDetails>{
         platformAndroid: const PlatformDetails(PlatformSupport.inline)
       });
+      writeFakeBuildGradle(plugin.getExamples().first, 'plugin1');
 
       final Directory androidDir =
           plugin.getExamples().first.platformDirectory(FlutterPlatform.android);
@@ -83,6 +118,9 @@ void main() {
           platformSupport: <String, PlatformDetails>{
             platformAndroid: const PlatformDetails(PlatformSupport.inline)
           });
+      for (final RepositoryPackage example in plugin.getExamples()) {
+        writeFakeBuildGradle(example, 'plugin1');
+      }
 
       final Iterable<Directory> exampleAndroidDirs = plugin.getExamples().map(
           (RepositoryPackage example) =>
@@ -140,6 +178,7 @@ void main() {
       ], platformSupport: <String, PlatformDetails>{
         platformAndroid: const PlatformDetails(PlatformSupport.inline)
       });
+      writeFakeBuildGradle(plugin.getExamples().first, 'plugin1');
 
       final String gradlewPath = plugin
           .getExamples()
@@ -167,6 +206,34 @@ void main() {
           ));
     });
 
+    test('fails if javac lint-warnings-as-errors is missing', () async {
+      final RepositoryPackage plugin =
+          createFakePlugin('plugin1', packagesDir, extraFiles: <String>[
+        'example/android/gradlew',
+      ], platformSupport: <String, PlatformDetails>{
+        platformAndroid: const PlatformDetails(PlatformSupport.inline)
+      });
+      writeFakeBuildGradle(plugin.getExamples().first, 'plugin1',
+          warningsConfigured: false);
+
+      Error? commandError;
+      final List<String> output = await runCapturingPrint(
+          runner, <String>['lint-android'], errorHandler: (Error e) {
+        commandError = e;
+      });
+
+      expect(commandError, isA<ToolExit>());
+      expect(
+          output,
+          containsAllInOrder(
+            <Matcher>[
+              contains('The example example is not configured to treat javac '
+                  'lints and warnings as errors.'),
+              contains('The following packages had errors:'),
+            ],
+          ));
+    });
+
     test('skips non-Android plugins', () async {
       createFakePlugin('plugin1', packagesDir);