[internals][types] Last part of internal refactor; Got rid of remaining flow errors

lib/modules/core/firebase-app.js

@@ -29,7 +29,7 @@ import type {
 const FirebaseCoreModule = NativeModules.RNFirebase;
 
 
-export default class FirebaseApp {
+export default class App {
   _extendedProps: { [string] : boolean };
   _initialized: boolean = false;
   _name: string;
@@ -119,6 +119,7 @@ export default class FirebaseApp {
         throw new Error(INTERNALS.STRINGS.ERROR_PROTECTED_PROP(key));
       }
 
+      // $FlowBug: Flow doesn't support indexable signatures on classes: https://github.com/facebook/flow/issues/1323
       this[key] = props[key];
       this._extendedProps[key] = true;
     }
@@ -145,7 +146,7 @@ export default class FirebaseApp {
    *
    * @return {*}
    */
-  onReady(): Promise<FirebaseApp> {
+  onReady(): Promise<App> {
     if (this._initialized) return Promise.resolve(this);
 
     return new Promise((resolve, reject) => {

lib/modules/core/firebase.js

@@ -6,7 +6,7 @@ import { NativeModules } from 'react-native';
 
 import APPS from '../../utils/apps';
 import INTERNALS from '../../utils/internals';
-import FirebaseApp from './firebase-app';
+import App from './firebase-app';
 
 // module imports
 import { statics as AdMobStatics, MODULE_NAME as AdmobModuleName } from '../admob';
@@ -88,7 +88,7 @@ class FirebaseCore {
    * @param name
    * @return {*}
    */
-  initializeApp(options: FirebaseOptions, name: string): FirebaseApp {
+  initializeApp(options: FirebaseOptions, name: string): App {
     return APPS.initializeApp(options, name);
   }
 
@@ -101,7 +101,7 @@ class FirebaseCore {
    * @param name
    * @return {*}
    */
-  app(name?: string): FirebaseApp {
+  app(name?: string): App {
     return APPS.app(name);
   }
 
@@ -109,7 +109,7 @@ class FirebaseCore {
    * A (read-only) array of all initialized apps.
    * @return {Array}
    */
-  get apps(): Array<FirebaseApp> {
+  get apps(): Array<App> {
     return APPS.apps();
   }
 }