Wi-Fi & Mobile Activity better drawables

This is just a temporary fix.
Better solution will be to use new vector format of drawables.

Change-Id: I2f27e5cedefefbf542fa9871d6dc125cb1420439
Signed-off-by: kecinzer <kecinzer@gmail.com>

Conflicts:
	packages/SystemUI/res/drawable-xhdpi/stat_sys_signal_in.png
	packages/SystemUI/res/drawable-xhdpi/stat_sys_signal_inout.png
	packages/SystemUI/res/drawable-xhdpi/stat_sys_signal_out.png
	packages/SystemUI/res/drawable-xhdpi/stat_sys_wifi_in.png
	packages/SystemUI/res/drawable-xhdpi/stat_sys_wifi_inout.png
	packages/SystemUI/res/drawable-xhdpi/stat_sys_wifi_out.png