Fix gestures for exclude-from-recents + translucent tasks

- If task is translucent and excluded, fade out as swipe up
  - Fade back in when re-launching live tile
- Ignore excluded tasks if there is another visible task,
  and use that underlying task during gesture instead.

Fixes: 299351175
Fixes: 300297333
Fixes: 302672319

Test: Invoke translucent + excluded app (e.g. expanded Volume
dialog) over another app, swipe to overview, quick switch, home

Change-Id: I5740afc4bf561d1a264bd132863ffc15f27d2b20