temporary fix for a memory leak

see: flutter/flutter#69305

Author: iskakaushik

shell/platform/darwin/ios/framework/Source/FlutterPlatformViews.mm

@@ -437,6 +437,12 @@
   for (UIView* sub_view in [flutter_view subviews]) {
     [sub_view removeFromSuperview];
   }
+  // See: https://github.com/flutter/flutter/issues/69305
+  for (auto it = touch_interceptors_.begin(); it != touch_interceptors_.end(); it++) {
+    FlutterTouchInterceptingView* view = it->second.get();
+    [view removeFromSuperview];
+  }
+  touch_interceptors_.clear();
   views_.clear();
   composition_order_.clear();
   active_composition_order_.clear();

testing/ios/IosUnitTests/IosUnitTests.xcodeproj/project.pbxproj

@@ -332,6 +332,7 @@
 /* Begin XCBuildConfiguration section */
 		0D6AB6D022BB05E200EEE540 /* Debug */ = {
 			isa = XCBuildConfiguration;
+			baseConfigurationReference = 0D6AB73E22BD8F0200EEE540 /* FlutterEngineConfig.xcconfig */;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				CLANG_ANALYZER_NONNULL = YES;
@@ -391,6 +392,7 @@
 		};
 		0D6AB6D122BB05E200EEE540 /* Release */ = {
 			isa = XCBuildConfiguration;
+			baseConfigurationReference = 0D6AB73E22BD8F0200EEE540 /* FlutterEngineConfig.xcconfig */;
 			buildSettings = {
 				ALWAYS_SEARCH_USER_PATHS = NO;
 				CLANG_ANALYZER_NONNULL = YES;
@@ -484,7 +486,6 @@
 		};
 		0D6AB6D622BB05E200EEE540 /* Debug */ = {
 			isa = XCBuildConfiguration;
-			baseConfigurationReference = 0D6AB73E22BD8F0200EEE540 /* FlutterEngineConfig.xcconfig */;
 			buildSettings = {
 				BUNDLE_LOADER = "$(TEST_HOST)";
 				CLANG_ALLOW_NON_MODULAR_INCLUDES_IN_FRAMEWORK_MODULES = YES;
@@ -528,7 +529,6 @@
 		};
 		0D6AB6D722BB05E200EEE540 /* Release */ = {
 			isa = XCBuildConfiguration;
-			baseConfigurationReference = 0D6AB73E22BD8F0200EEE540 /* FlutterEngineConfig.xcconfig */;
 			buildSettings = {
 				BUNDLE_LOADER = "$(TEST_HOST)";
 				CLANG_ALLOW_NON_MODULAR_INCLUDES_IN_FRAMEWORK_MODULES = YES;

testing/ios/IosUnitTests/IosUnitTests.xcodeproj/xcshareddata/xcschemes/IosUnitTests.xcscheme

@@ -28,6 +28,13 @@
       selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
       shouldUseLaunchSchemeArgsEnv = "YES"
       systemAttachmentLifetime = "keepNever">
+      <AdditionalOptions>
+         <AdditionalOption
+            key = "MallocStackLogging"
+            value = ""
+            isEnabled = "YES">
+         </AdditionalOption>
+      </AdditionalOptions>
       <Testables>
          <TestableReference
             skipped = "NO">