Add notice on v1 embedding removal to 3.29.0 breaking changes (#11749)

The deletion of the v1 embedding
(flutter/engine#51229) should have had an
associated breaking changes notice. Unfortunately this was missed, under
the assumption that a flutter tool check would have caught references to
the v1 embedding in an earlier release, and provided upgrade
instructions.

Resolves flutter/flutter#164024


---------

Co-authored-by: Gray Mackall <[email protected]>
Co-authored-by: Parker Lougheed <[email protected]>

Author: 3 people

src/content/release/breaking-changes/index.md

@@ -59,12 +59,14 @@ They're sorted by release and listed in alphabetical order:
 <a id="released-in-flutter-329" aria-hidden="true"></a>
 ### Released in Flutter 3.29
 
+* [Removal of v1 Android embedding Java APIs][]
 * [Deprecate `WebGoldenComparator`][]
 * [Deprecate `ThemeData.dialogBackgroundColor` in favor of `DialogThemeData.backgroundColor`][]
 * [`ImageFilter.blur` default tile mode automatic selection][]
 * [Updated Material 3 `Slider`][]
 * [Updated Material 3 progress indicators][]
 
+[Removal of v1 Android embedding Java APIs]: /release/breaking-changes/v1-android-embedding
 [Deprecate `WebGoldenComparator`]: /release/breaking-changes/web-golden-comparator
 [Deprecate `ThemeData.dialogBackgroundColor` in favor of `DialogThemeData.backgroundColor`]: /release/breaking-changes/deprecate-themedata-dialogbackgroundcolor
 [`ImageFilter.blur` default tile mode automatic selection]: /release/breaking-changes/image-filter-blur-tilemode

src/content/release/breaking-changes/v1-android-embedding.md

@@ -0,0 +1,77 @@
+---
+title: Removal of v1 Android embedding Java APIs
+description: >-
+  Learn how to account for the removal of the Android v1 embedding APIs.
+---
+
+## Summary
+
+Android's v1 embedding has been removed in Flutter 3.29.0.
+This follows the deprecation described in
+[Android v1 embedding app and plugin creation deprecation][].
+The following is a full list of classes removed.
+
+```text
+io.flutter.app.FlutterActivity
+io.flutter.app.FlutterActivityDelegate
+io.flutter.app.FlutterActivityEvents
+io.flutter.app.FlutterApplication
+io.flutter.app.FlutterFragmentActivity
+io.flutter.app.FlutterPlayStoreSplitApplication
+io.flutter.app.FlutterPluginRegistry
+
+io.flutter.embedding.engine.plugins.shim.ShimPluginRegistry
+io.flutter.embedding.engine.plugins.shim.ShimRegistrar
+
+io.flutter.view.FlutterMain
+io.flutter.view.FlutterNativeView
+io.flutter.view.FlutterView
+```
+
+If your project references any of the above classes, consult the following
+list for instructions on migration.
+
+* `io.flutter.app.FlutterActivity` was
+   replaced with `io.flutter.embedding.android.FlutterActivity`.
+* `io.flutter.app.FlutterActivityDelegate` was
+   replaced with `io.flutter.embedding.android.FlutterActivityAndFragmentDelegate`.
+* `io.flutter.app.FlutterActivityEvents` was removed.
+* `io.flutter.app.FlutterApplication` was removed.
+   Flutter projects with custom `Application` implementations should
+   instead extend the base `android.app.Application`.
+* `io.flutter.app.FlutterFragmentActivity` was
+  replaced with `io.flutter.embedding.android.FlutterFragmentActivity`.
+* `io.flutter.app.FlutterPlayStoreSplitApplication` was
+  replaced with `io.flutter.embedding.android.FlutterPlayStoreSplitApplication`.
+* `io.flutter.app.FlutterPluginRegistry` was removed,
+   as it only served to let plugins support apps using the v1 embedding.
+* `io.flutter.embedding.engine.plugins.shim.ShimPluginRegistry` was removed,
+   as it only served to support let plugins support apps using the v1 embedding.
+* `io.flutter.embedding.engine.plugins.shim.ShimRegistrar` was removed,
+   as it only served to support let plugins support apps using the v1 embedding.
+* `io.flutter.view.FlutterMain` was
+   replaced by `io.flutter.embedding.engine.loader.FlutterLoader`.
+* `io.flutter.view.FlutterNativeView` was
+   replaced by `io.flutter.embedding.android.FlutterView`.
+* `io.flutter.view.FlutterView` was
+   replaced by `io.flutter.embedding.android.FlutterView`.
+
+[Android v1 embedding app and plugin creation deprecation]: /release/breaking-changes/android-v1-embedding-create-deprecation
+
+## Plugin authors
+
+Plugins should remove the `registerWith` method from
+their `FlutterPlugin` interface implementation:
+
+```java
+public static void registerWith(@NonNull io.flutter.plugin.common.PluginRegistry.Registrar registrar);
+```
+
+For an example of this migration,
+check out the pull request to remove this method from the
+Flutter team-owned plugins: https://github.com/flutter/packages/pull/6494.
+
+## Timeline
+
+Landed in version: 3.28.0-0.1.pre<br>
+In stable release: 3.29