Remove deprecated PullToRefreshViewAndroid and onRefreshStart / endRefreshing

Summary:
Removes the deprecated APIs that were replaced by `RefreshControl`. Those API have been deprecated for a while already so I think it's fine to remove them at this point. Also ported the `SwipeRefreshLayoutTestModule` test to use `RefreshControl` instead of `PullToRefreshViewAndroid`.

**Test plan (required)**

Made sure no references are left in the codebase to `PullToRefreshViewAndroid`, `onRefreshStart` and `endRefreshing`.
Tested that `ScrollView` examples in UIExplorer still work properly.
Check that the `SwipeRefreshLayoutTestModule` passes on CI.
Closes https://github.com/facebook/react-native/pull/7447

Reviewed By: mkonicek

Differential Revision: D3292391

Pulled By: bestander

fbshipit-source-id: 27eb2443861e04a9f7319586ce2ada381b714d47

ReactAndroid/src/androidTest/js/SwipeRefreshLayoutTestModule.js

@@ -15,7 +15,7 @@ var BatchedBridge = require('BatchedBridge');
 var React = require('React');
 var RecordingModule = require('NativeModules').SwipeRefreshLayoutRecordingModule;
 var ScrollView = require('ScrollView');
-var PullToRefreshViewAndroid = require('PullToRefreshViewAndroid');
+var RefreshControl = require('RefreshControl');
 var Text = require('Text');
 var TouchableWithoutFeedback = require('TouchableWithoutFeedback');
 var View = require('View');
@@ -62,13 +62,17 @@ var SwipeRefreshLayoutTestApp = React.createClass({
       rows.push(<Row key={i} />);
     }
     return (
-      <PullToRefreshViewAndroid
+      <ScrollView
         style={{flex: 1}}
-        onRefresh={() => RecordingModule.onRefresh()}>
-        <ScrollView style={{flex: 1}}>
-          {rows}
-        </ScrollView>
-      </PullToRefreshViewAndroid>
+        refreshControl={
+          <RefreshControl
+            style={{flex: 1}}
+            refreshing={false}
+            onRefresh={() => RecordingModule.onRefresh()}
+          />
+        }>
+        {rows}
+      </ScrollView>
     );
   },
 });