Highlight the clear button in the recents view when clicked

This commit also makes copies of the ic_notify drawables for the recents
panel to avoid any collisions with possible future changes to the
notification bar UI. (The pressed state drawable was already an unused
leftover resource).

Change-Id: Ib0d5982e80771b6639efd25ac792ebfe9f1ca1c5
Merge remote-tracking branch 'upstream/cm-10.1' into cm-10.1