Disable some flaky tests (#4274)

These tests are failing frequently, and interfering with the tree
staying open.

Tracking issues:
flutter/flutter#88837
flutter/flutter#86915
flutter/flutter#86757

Author: stuartmorgan-g

packages/android_alarm_manager/example/android/app/src/androidTest/java/io/plugins/androidalarmmanager/BackgroundExecutionTest.java

@@ -17,6 +17,7 @@
 import androidx.test.ext.junit.runners.AndroidJUnit4;
 import androidx.test.rule.ActivityTestRule;
 import org.junit.Before;
+import org.junit.Ignore;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -39,6 +40,7 @@ public void setUp() throws Exception {
     ActivityScenario.launch(DriverExtensionActivity.class);
   }
 
+  @Ignore("Disabled due to flake: https://github.com/flutter/flutter/issues/88837")
   @Test
   public void startBackgroundIsolate() throws Exception {
 

packages/video_player/video_player/example/integration_test/video_player_test.dart

@@ -220,6 +220,9 @@ void main() {
 
       await tester.pumpAndSettle();
       expect(_controller.value.isPlaying, true);
-    }, skip: kIsWeb); // Web does not support local assets.
+    },
+        skip: kIsWeb || // Web does not support local assets.
+            // Extremely flaky on iOS: https://github.com/flutter/flutter/issues/86915
+            defaultTargetPlatform == TargetPlatform.iOS);
   });
 }

packages/webview_flutter/webview_flutter/example/integration_test/webview_flutter_test.dart

@@ -1330,7 +1330,9 @@ void main() {
     await pageLoaded.future;
     final String? currentUrl = await controller.currentUrl();
     expect(currentUrl, 'https://flutter.dev/');
-  });
+  },
+      // Flaky on Android: https://github.com/flutter/flutter/issues/86757
+      skip: Platform.isAndroid);
 
   // TODO(bparrishMines): skipped due to https://github.com/flutter/flutter/issues/86757.
   testWidgets(