Use .9.png images for quick settings tile background.

Change-Id: I17cd77006e8da2fe629d63e0932c88041e81f07c
Make notification_header_bg a .9.png for better theming

Change-Id: I477872ac49b1bbb77e44b9aa9bedd4d27643ea4f
Signed-off-by: Chester Kener <Cl3Kener@gmail.com>

Conflicts:
	packages/SystemUI/res/layout/status_bar_expanded_header.xml
	packages/SystemUI/res/values/colors.xml