Invalidate talkback accessibility tree after transitioning

Using AutoTransition seems to allow the talkback accessibility nodes to
stay out of sync if the user starts iterating the view during the
transition. Calling `notifySubtreeAccessibilityStateChangedIfNeeded()`
on the end of the transition gets us back into the correct state.

Test: manual; start iterating view via talkback swiping while the
channel dialog editor transitions between app notifications on/off
Fixes: 133822221

Change-Id: I7218bc0734cf05372b8fbecfb6eeef69cb3f1d40