Summary:
Changes React Native so that when `accessibilityState` is used to change a view from `selected: true` to `selected: false`, the change in state is announced.
This is how `checked` works; it is unclear why Android does not do this for `selected`, too.
Changelog:
[Android][Added] - TalkBack now announces "unselected" when changing `accessibilityState.selected` to false.
Reviewed By: blavalla
Differential Revision: D27449293
fbshipit-source-id: a6d77b55d63655973ad93c4d5e3743742501f378