Non intrusive incall ui, (3/4):

Thanks to OmniRom:
https://github.com/omnirom/android_packages_apps_InCallUI/commit/2ac98feb73e9b195a7bc797eb1f060bbe3d93e88
https://github.com/omnirom/android_packages_apps_InCallUI/commit/2463f41af9d362552780dac44c88f46fb46f90a6
https://github.com/omnirom/android_packages_apps_InCallUI/commit/268b0b05def6d8c103aed90fc4c6b6163df59101
https://github.com/omnirom/android_packages_apps_InCallUI/commit/1171982b870a2cf6f3305e7eaffe3d16a46eaa35
https://github.com/omnirom/android_packages_apps_InCallUI/commit/c9005fdad86d3b4f924d4e8a492047f6b0258ab0

- Enable/disable Non intrusive incall ui
- Click the back button to put the incall ui in the background
  (answer/dismiss the call from staus bar)

Conflicts:
	res/values/dimens.xml