Convert com.facebook.react.runtime.ReactInstance to Kotlin (facebook#50664)

Summary:
Pull Request resolved: facebook#50664

Changelog: [Internal]

Reviewed By: mlord93

Differential Revision: D72804418

fbshipit-source-id: 776adcb4c6cd6ad867525ac28cda8089c56f1ae5

Author: javache

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

@@ -674,7 +674,7 @@ FabricUIManager getUIManager() {
     if (reactInstance == null) {
       return null;
     }
-    return reactInstance.getUIManager();
+    return reactInstance.getFabricUIManager();
   }
 
   /* package */ <T extends NativeModule> boolean hasNativeModule(Class<T> nativeModuleInterface) {