Fixing some bugs in Recents keyboard behaviour.

- Ensuring that we don't allow meta-tab to trigger Recents (since meta is a system key now)
- Adding dpad keys support to traverse stack
- Adding workaround for cases where tasks wouldn't be focused depending on how you launch Recents

Change-Id: I4101ced7e47e0d1659d5fa236214be5697c00560
6 files changed