[CP-stable]Fix another instance of platform view breakage on Android …

…14 (#52982)

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### Issue Link

Fixes flutter/flutter#148662
CP bug flutter/flutter#148885

### Target

stable

### PR Link

TBD

### Changelog Description

Platform view fix for android 14 when multiple activities are used and onMemoryTrim is called. 

### Impacted Users

Users shipping flutter apps on android 14 that use platform viewss 

### Impact Description

Platform views stop rendering new frames. 

### Workaround

No app level work around. 

### Risk

low

### Test Coverage

no

### Validation Steps

App is launched
App is backgrounded (via a back-gesture swipe)
Android Bug triggers HERE
no onTrimMemory callback fires
App is resumed
Platform views don't render

shell/platform/android/io/flutter/embedding/android/FlutterActivityAndFragmentDelegate.java

@@ -9,6 +9,7 @@
 
 import android.annotation.TargetApi;
 import android.app.Activity;
+import android.content.ComponentCallbacks2;
 import android.content.Context;
 import android.content.Intent;
 import android.net.Uri;
@@ -645,6 +646,12 @@ void onStop() {
     // See https://github.com/flutter/flutter/issues/93276
     previousVisibility = flutterView.getVisibility();
     flutterView.setVisibility(View.GONE);
+    if (flutterEngine != null) {
+      // When an Activity is stopped it won't have its onTrimMemory callback invoked. Normally,
+      // this isn't a problem but because of a bug in some builds of Android 14 we must act as
+      // if the onTrimMemory callback has been called.
+      flutterEngine.getRenderer().onTrimMemory(ComponentCallbacks2.TRIM_MEMORY_BACKGROUND);
+    }
   }
 
   /**