Ability to disable/lock the android ViewPager scroll from props

Summary:
This is a nice feature to have.

I've tested this by copying and renaming the ViewPager java and javascript files from the react-native repo and including them in a project. Whats the best way to test this directly from the repo?
Closes https://github.com/facebook/react-native/pull/5968

Differential Revision: D3240651

Pulled By: mkonicek

fbshipit-source-id: 5f1d157216df4f3314915496188a92aec1b85e91

Examples/UIExplorer/ViewPagerAndroidExample.android.js

@@ -109,6 +109,7 @@ var ViewPagerAndroidExample = React.createClass({
     return {
       page: 0,
       animationsAreEnabled: true,
+      scrollEnabled: true,
       progress: {
         position: 0,
         offset: 0,
@@ -167,6 +168,7 @@ var ViewPagerAndroidExample = React.createClass({
         <ViewPagerAndroid
           style={styles.viewPager}
           initialPage={0}
+          scrollEnabled={this.state.scrollEnabled}
           onPageScroll={this.onPageScroll}
           onPageSelected={this.onPageSelected}
           onPageScrollStateChanged={this.onPageScrollStateChanged}
@@ -174,6 +176,13 @@ var ViewPagerAndroidExample = React.createClass({
           ref={viewPager => { this.viewPager = viewPager; }}>
           {pages}
         </ViewPagerAndroid>
+        <View style={styles.buttons}>
+          <Button
+            enabled={true}
+            text={this.state.scrollEnabled ? 'Scroll Enabled' : 'Scroll Disabled'}
+            onPress={() => this.setState({scrollEnabled: !this.state.scrollEnabled})}
+          />
+        </View>
         <View style={styles.buttons}>
           { animationsAreEnabled ?
             <Button

Libraries/Components/ViewPager/ViewPagerAndroid.android.js

@@ -128,7 +128,7 @@ var ViewPagerAndroid = React.createClass({
     * When false, the content does not scroll.
     * The default value is true.
     */
-    scrollEnabled: React.PropTypes.bool,
+    scrollEnabled: ReactPropTypes.bool,
   },
 
   componentDidMount: function() {

ReactAndroid/src/main/java/com/facebook/react/views/viewpager/ReactViewPager.java

@@ -142,7 +142,11 @@ import com.facebook.react.uimanager.events.NativeGestureUtil;
 
   @Override
   public boolean onInterceptTouchEvent(MotionEvent ev) {
-    if (mScrollEnabled && super.onInterceptTouchEvent(ev)) {
+    if (!mScrollEnabled) {
+      return false;
+    }
+
+    if (super.onInterceptTouchEvent(ev)) {
       NativeGestureUtil.notifyNativeGestureStarted(this, ev);
       return true;
     }
@@ -154,6 +158,7 @@ import com.facebook.react.uimanager.events.NativeGestureUtil;
     if (!mScrollEnabled) {
       return false;
     }
+
     return super.onTouchEvent(ev);
   }