InCallUI: fix blue call button background on some devices

Fixes reports of this: http://goo.gl/zTgVGQ

PS2: A little bit darker.
Change-Id: I2097018811aa7852604e987b9142a4c3d4aa4a30
InCallUI: Heads up meets SlimKat....SlimKat meets Google IO [2/4]

Add native heads up support on dialer.

We only have show call in background feature. We combine it now with heads up.
So it is doing exactly same like on Google IO was shown.

Enabled by default.

- Notification is expanded by default
- Send as requested to force show the heads up no matter what.

Change-Id: I819316226f990058e6da6c289b8424d80ac1456e