Fix stack overflow in createRootView (#43420)

Summary:
Pull Request resolved: #43420

Calling `mReactDelegate.createRootView` just ends up calling the overridden method in the anonymous inner class. Instead have the base implementation return null, and call super.

Changelog: [Internal]

Reviewed By: jessebwr, janeli-100005636499545

Differential Revision: D54772205

fbshipit-source-id: fc90e6718f9c287e8b86e5768cf7f74d0db06c49

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

@@ -63,8 +63,13 @@ public ReactActivityDelegate(
     return getLaunchOptions();
   }
 
+  /**
+   * Override to customize ReactRootView creation.
+   *
+   * <p>Not used on bridgeless
+   */
   protected ReactRootView createRootView() {
-    return Assertions.assertNotNull(mReactDelegate).createRootView();
+    return null;
   }
 
   /**
@@ -102,7 +107,11 @@ public void onCreate(Bundle savedInstanceState) {
               getPlainActivity(), getReactNativeHost(), mainComponentName, launchOptions) {
             @Override
             protected ReactRootView createRootView() {
-              return ReactActivityDelegate.this.createRootView();
+              ReactRootView rootView = ReactActivityDelegate.this.createRootView();
+              if (rootView == null) {
+                rootView = super.createRootView();
+              }
+              return rootView;
             }
           };
     }