Make CameraRoll work with Promises

Summary:
public
This is the first module moving to the new model of working with Promises.

We now warn on uses of callback version.  At some point we will remove that.

Reviewed By: davidaurelio

Differential Revision: D2849811

fb-gh-sync-id: 8a31924cc2b438efc58f3ad22d5f27c273563472

Libraries/Utilities/Platform.android.js

@@ -12,11 +12,9 @@
 
 'use strict';
 
-var AndroidConstants = require('NativeModules').AndroidConstants;
-
 var Platform = {
   OS: 'android',
-  Version: AndroidConstants.Version,
+  get Version() { return require('NativeModules').AndroidConstants.Version; },
 };
 
 module.exports = Platform;