HOVER: Theme Engine compatibilities and some resources tweaks

Use default notification dimens, avoid setting a custom one.
A bit of cleanup too.

Notifications:
Hardcode dimensions to android defaults. Avoid themes to change them,
Ribbons feature (present on CM based roms mostly) needs that.

Thanks to +John Xionidis to help me trick this out for full CM11 made themes :)

Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Change-Id: Iccf12061c045c29db4bc73736dac68e52dda198c

Conflicts:
	packages/SystemUI/res/values/dimens_custom.xml