Fix Android app stuck in splash screen when killed by the OS (#1403)

android/app/src/main/java/com/mattermost/rnbeta/MainApplication.java

@@ -93,6 +93,13 @@ public class MainApplication extends NavigationApplication implements INotificat
     SoLoader.init(this, /* native exopackage */ false);
   }
 
+  @Override
+  public boolean clearHostOnActivityDestroy() {
+    // This solves the issue where the splash screen does not go away
+    // after the app is killed by the OS cause of memory or a long time in the background
+    return false;
+  }
+
   @Override
   public IPushNotification getPushNotification(Context context, Bundle bundle, AppLifecycleFacade defaultFacade, AppLaunchHelper defaultAppLaunchHelper) {
     return new CustomPushNotification(