Implement release of FabricUIManager resources

Reviewed By: achen1

Differential Revision: D8232155

fbshipit-source-id: 6683c692a830f5a73aab2c606167e54d668ae5c2

ReactAndroid/src/androidTest/java/com/facebook/react/testing/idledetection/ReactBridgeIdleSignaler.java

@@ -30,6 +30,11 @@ public class ReactBridgeIdleSignaler implements NotThreadSafeBridgeIdleDebugList
     mBridgeIdleSemaphore.release();
   }
 
+  @Override
+  public void onBridgeDestroyed() {
+    // Do nothing
+  }
+
   @Override
   public void onTransitionToBridgeBusy() {
     mIsBridgeIdle = false;