Update alignment for gear / snooze icons to shift when expanded

How do the icons get placed?
- Ideally they are centered in the “normal” notification height
- If the notification is larger than that, they remain in the same place
- If the notification is smaller than that they are centered in the
  remaining space
- If the height changes while showing, they shift

Test: manual - have min notification, show gear / snooze, expand it
      note that the gear / snooze icons shift when expanded. Also
      tested on variety of sized notifications (big picture, custom
      view + groups)
Fixes: 37922756

Change-Id: I6a2d8cd9e76e5a816adf79d052c4e15cf855886b