Clean up Halo stuff.

Change-Id: I565fbb272254354e1909668f7467d22065e66ee8

Conflicts:

	packages/SystemUI/res/drawable-hdpi/halo_bg.png
	packages/SystemUI/res/drawable-nodpi/bubble_l.9.png
	packages/SystemUI/res/drawable-nodpi/bubble_r.9.png
	packages/SystemUI/res/drawable-xhdpi/halo_bg.png