Summary:
Keep `PullToRefreshViewAndroid` consistent with other components that allow optimization through `setNativeProps`.
Also updates the example to make sure it is working.
Closes https://github.com/facebook/react-native/pull/4771
Reviewed By: svcscm
Differential Revision: D2756033
Pulled By: androidtrunkagent
fb-gh-sync-id: a1f483a3809f01bca06a6a09498f9a89fd65f572