Add snapToAlignment to ScrollView.js Android implementation
Add snapToAlignment to ScrollView.js Android implementation

Summary:
Update ScrollView.js to support snapToAlignment in RN Android

changelog: [Android][Added] Implement snapToAlignment in ReactHorizontalScrollView

Reviewed By: JoshuaGross

Differential Revision: D31174546

fbshipit-source-id: 480e990793ced74121c6aa1875f2695a70d1f804

janicduplessis/react-native,facebook/react-native,facebook/react-native,javache/react-native,facebook/react-native,janicduplessis/react-native,javache/react-native,facebook/react-native,facebook/react-native,janicduplessis/react-native,javache/react-native,javache/react-native,javache/react-native,janicduplessis/react-native,javache/react-native,facebook/react-native,facebook/react-native,facebook/react-native,janicduplessis/react-native,javache/react-native,janicduplessis/react-native,janicduplessis/react-native,javache/react-native,javache/react-native,janicduplessis/react-native,facebook/react-native