FB: Slimrecents background color && transparency [2/2]

PS: now setting sticks through reboots and TRDS state
        changes. also, add reset to default color option.

PS: when resetting to default, use TRDS (png) resources
        instead of custom color

PS: remove LSN dependency

PS: make default background setting cognizant of
        recent panel gravity setting to display
        correct background resource

Conflicts:
	packages/SystemUI/src/com/android/systemui/slimrecent/RecentController.java

Change-Id: I5c81db94edb37ccdbd4943da11de9a277d6fe0fe