[Reland] Fix touch focus not updated correctly after launching overview with live tile.

- Set touch mode to false at the first dpad left or right key event, since the framework doesn't do so in the live tile case
- Clear focus at any motion event

Similar to ag/19938037

Fixes: 277625965
Test: Meta+Tab to launch overview from app, or swipe from app, then use DPAD_LEFT and DPAD_RIGHT to go through overview. Make sure the selected task is highlighted. Also make sure swipe up to overview and go home doesn't highlight any icons on the home screen
Change-Id: I7afa46af7eb1cd826d2dc893583685936721868a