HALO: drawables are completely fucked

-Fix wrong size png's
-Add missing png's
-Make all png's more consistant
Signed-off-by: Paul Beeler <sparksco@gmail.com>

Conflicts:
	packages/SystemUI/res/drawable-hdpi/halo_back_left.png
	packages/SystemUI/res/drawable-hdpi/halo_back_right.png
	packages/SystemUI/res/drawable-hdpi/halo_bigred.png
	packages/SystemUI/res/drawable-hdpi/halo_black_x.png
	packages/SystemUI/res/drawable-hdpi/halo_dismiss.png
	packages/SystemUI/res/drawable-hdpi/ic_notify_halo_normal_grey.png
	packages/SystemUI/res/drawable-mdpi/halo_back_left.png
	packages/SystemUI/res/drawable-mdpi/halo_back_right.png
	packages/SystemUI/res/drawable-mdpi/halo_bg.png
	packages/SystemUI/res/drawable-mdpi/halo_bigred.png
	packages/SystemUI/res/drawable-mdpi/halo_black_x.png
	packages/SystemUI/res/drawable-mdpi/halo_dismiss.png
	packages/SystemUI/res/drawable-mdpi/ic_notify_halo_normal_grey.png
	packages/SystemUI/res/drawable-xhdpi/ic_notification_overlay.9.png

Change-Id: Ifcdb2a1904b230f0fa565c56c573143de186c831