Reset RootView ID when root view is detached from view hierarchy

Summary:
I have a theory that T53114059 can be caused by (1) other crashes, and/or (2) reloads. Clear out the ID of a RootView when it is detached.

Changelog: [Internal]

Reviewed By: mdvacca

Differential Revision: D21732066

fbshipit-source-id: 5e607f34cf42ca26bdf199d5d3024fd49a60dc1e

ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManager.java

@@ -840,6 +840,9 @@ public class ReactInstanceManager {
           detachViewFromInstance(reactRoot, currentContext.getCatalystInstance());
         }
       }
+
+      // Reset reactRoot content in case it's reused
+      clearReactRoot(reactRoot);
     }
   }