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
Use wifi_combo_margin_right for theming of space between status icons

Change-Id: I3b24479fa8e88a71c26bb1f1aae7e862cacab48e