AOD: Fix fallout from new Ambient Display

- Double tap on shelf did not wake up phone
- Calculate content height hint after setting new visible type
- Clean up content hint calculation for type ambient

Test: Trigger ambient disply. Observe that clicking on shelf works. Observe that the actions are not cut off.
Change-Id: I494fdd9f75e0fc3243d801f7d8f209eec44d2d84