Resolve Paper leak on Android (facebook#46896)

Summary:

On Android Paper UIManager, when calling `ReactRootView.unmountReactApplication`, the ReactRootView tag is unset [here](https://github.com/facebook/react-native/blob/main/packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManager.java#L926), before the round trip unmount operation to JS makes it's way back to a `dropView` call on `NativeViewHierarchyManager`.

In practice, this means that legacy architecture apps that unmount surfaces via `ReactRootView.unmountReactApplication` leak references to Views, and the "finalization" step (`onDropViewInstance`) is not universally called.

This is an attempt to fix the issue by skipping the `clearReactRoot` step on Paper, instead waiting for the round trip `UIManager.removeRootView` call.

## Changelog

[Android][Fixed] Fix issue where `onDropViewInstance` cleanup was not being handled after `ReactRootView.unmountReactApplication`

Differential Revision: D64054042

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManager.java

@@ -1391,14 +1391,14 @@ private void detachRootViewFromInstance(ReactRoot reactRoot, ReactContext reactC
             new RuntimeException(
                 "detachRootViewFromInstance called with ReactRootView with invalid id"));
       }
+
+      clearReactRoot(reactRoot);
     } else {
       reactContext
           .getCatalystInstance()
           .getJSModule(AppRegistry.class)
           .unmountApplicationComponentAtRootTag(reactRoot.getRootViewTag());
     }
-
-    clearReactRoot(reactRoot);
   }
 
   @ThreadConfined(UI)

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/NativeViewHierarchyManager.java

@@ -674,6 +674,7 @@ public synchronized void removeRootView(int rootViewTag) {
     View rootView = mTagsToViews.get(rootViewTag);
     dropView(rootView);
     mRootTags.delete(rootViewTag);
+    rootView.setId(View.NO_ID);
   }
 
   /**