Make ReactHost.createSurface() method non nullable (#47189)

Summary:
Pull Request resolved: #47189

ReactHost.createSurface() should not return a nullable surface, I'm changing that here.

changelog: [Android][Breaking] Make ReactHost.createSurface() method non nullable

Reviewed By: tdn120

Differential Revision: D64910107

fbshipit-source-id: ce8c5efd2c1e36eba0a85ae89cd1cd2a6305e885

Author: mdvacca

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

@@ -84,7 +84,7 @@ public interface ReactHost {
       context: Context,
       moduleName: String,
       initialProps: Bundle?
-  ): ReactSurface?
+  ): ReactSurface
 
   /**
    * This function can be used to initialize the ReactInstance in a background thread before a