Add specs for ModalManager (#24896)

Summary:
Part of #24875

## Changelog
[General] [Added] - Add TurboModule spec for ModalManager
Pull Request resolved: #24896

Reviewed By: rickhanlonii

Differential Revision: D15471097

Pulled By: fkgozali

fbshipit-source-id: 99671583ddc2a6fc32fd1bcf9a6e340ad93a27c2

Libraries/Modal/Modal.js

@@ -13,18 +13,17 @@
 const AppContainer = require('../ReactNative/AppContainer');
 const I18nManager = require('../ReactNative/I18nManager');
 const NativeEventEmitter = require('../EventEmitter/NativeEventEmitter');
-const NativeModules = require('../BatchedBridge/NativeModules');
+import NativeModalManager from './NativeModalManager';
 const Platform = require('../Utilities/Platform');
 const React = require('react');
 const PropTypes = require('prop-types');
 const StyleSheet = require('../StyleSheet/StyleSheet');
 const View = require('../Components/View/View');
 
 const RCTModalHostView = require('./RCTModalHostViewNativeComponent');
-
 const ModalEventEmitter =
-  Platform.OS === 'ios' && NativeModules.ModalManager
-    ? new NativeEventEmitter(NativeModules.ModalManager)
+  Platform.OS === 'ios' && NativeModalManager != null
+    ? new NativeEventEmitter(NativeModalManager)
     : null;
 
 import type EmitterSubscription from '../vendor/emitter/EmitterSubscription';

Libraries/Modal/NativeModalManager.js

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow
+ * @format
+ */
+
+'use strict';
+
+import type {TurboModule} from 'RCTExport';
+import * as TurboModuleRegistry from 'TurboModuleRegistry';
+
+export interface Spec extends TurboModule {
+  // RCTEventEmitter
+  +addListener: (eventName: string) => void;
+  +removeListeners: (count: number) => void;
+}
+
+export default TurboModuleRegistry.get<Spec>('ModalManager');