Remove references to enableFabricStopAllSurfacesOnTeardown

Summary:
According to our experiments it's not better than "stop surface on unmount" in any way, and might regress some metrics. Unclear why, but if it's not necessary and doesn't seem to help, it doesn't make sense to continue this experiment.

We still have a mechanism on the C++ side to stop outstanding surfaces on teardown that does the same thing.

Changelog: [Internal]

Reviewed By: mdvacca

Differential Revision: D22318864

fbshipit-source-id: 7e678c63e4884382e57d996a7f4c4b7b24c8193a

ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java

@@ -81,9 +81,6 @@ public class ReactFeatureFlags {
   /** Feature flag to configure initialization of Fabric surfaces. */
   public static boolean enableFabricStartSurfaceWithLayoutMetrics = true;
 
-  /** Feature flag to have FabricUIManager teardown stop all active surfaces. */
-  public static boolean enableFabricStopAllSurfacesOnTeardown = false;
-
   /** Feature flag to use stopSurface when ReactRootView is unmounted. */
   public static boolean enableStopSurfaceOnRootViewUnmount = false;
 }

ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java

@@ -297,15 +297,6 @@ public class FabricUIManager implements UIManager, LifecycleEventListener {
     // memory immediately.
     mDispatchUIFrameCallback.stop();
 
-    // Stop all attached surfaces
-    if (ReactFeatureFlags.enableFabricStopAllSurfacesOnTeardown) {
-      FLog.e(TAG, "stop all attached surfaces");
-      for (int surfaceId : mReactContextForRootTag.keySet()) {
-        FLog.e(TAG, "stop attached surface: " + surfaceId);
-        stopSurface(surfaceId);
-      }
-    }
-
     mBinding.unregister();
     mBinding = null;