Send HEADERS_RECEIVED and LOADING events on Android

Summary: Send part of the response body every 100 ms if the client has set onreadystatechange. This
is done by using the same events as the iOS code and removing the callback that Android previously
used.

Reconsolidate iOS and Android implementations.

Closes #3772

public

Reviewed By: mkonicek

Differential Revision: D2647005

fb-gh-sync-id: d006e566867fa47d5f8dff71219cb390bcb8e15a

Libraries/Network/RCTNetworking.ios.js

@@ -0,0 +1,13 @@
+/**
+ * Copyright (c) 2015-present, Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD-style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ *
+ * @providesModule RCTNetworking
+ */
+'use strict';
+
+module.exports = require('NativeModules').Networking;