Prefetching of accessibility node infos getting incorrect views.

1. The prefetcher of accessibility nodes infos was not folloing
   the childForAccessibility relationship when finding the views
   whose node infos to prefetch.

2. NumberPicker was not reporting the correct parent.

bug:6471710

Change-Id: Ia7ad5dd031fb4b3816dfe630d5212201cfafa236
4 files changed