Frameworks: Lockscreen custom wallpaper (1/2)

kitkat now has code for a custom wallpaper image.

Using that code set a switch case to set the custom background between
	- Color Fill
	- Custom Wallpaper
	- Default background

This way allows the same overlay shadow thats set on the keyguard when
its the defualt way. And the overlay effect works on both color fill and
custom image.

PatchSet 3: Missed the simple fact this also sets the album art when
            transport view is active. This fixes that.

PatchSet 4: edit commit message.

PatchSet 5: rebase to work with commit b3c0350c9f48dcdaa46326792b21964a246f76d5

PatchSet 6: fix commit message.

PatchSet 7: fix background not setting after a screen on screen off then
            screen on.

Change-Id: I98fde63ef9f3c0a5f334cd9a97b237a6f99c57f6

Patchset: 7
http://review.cyanogenmod.org/#/c/54965/