HALO: hdpi & mdpi icon update

time to refresh these outdated icons

Change-Id: If7bf3915c6d3b23fe940f786092689133064bd82

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_bg.png
	packages/SystemUI/res/drawable-hdpi/halo_bigred.png
	packages/SystemUI/res/drawable-hdpi/halo_black_x.png
	packages/SystemUI/res/drawable-hdpi/halo_clear_all.png
	packages/SystemUI/res/drawable-hdpi/halo_dismiss.png
	packages/SystemUI/res/drawable-hdpi/halo_marker.png
	packages/SystemUI/res/drawable-hdpi/halo_message.png
	packages/SystemUI/res/drawable-hdpi/halo_silence_left.png
	packages/SystemUI/res/drawable-hdpi/halo_silence_right.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_clear_all.png
	packages/SystemUI/res/drawable-mdpi/halo_dismiss.png
	packages/SystemUI/res/drawable-mdpi/halo_marker.png
	packages/SystemUI/res/drawable-mdpi/halo_message.png
	packages/SystemUI/res/drawable-mdpi/halo_silence_left.png
	packages/SystemUI/res/drawable-mdpi/halo_silence_right.png