incallui: fix callbuttons xxhdpi images

Fix addParticipant and modifyCall images to properly fit in xxhdpi resolutions

Change-Id: I9f1ff0517a86a25660295f1302d0d20e2482fd12
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>

Conflicts:
	res/drawable-hdpi/ic_switch_video_holo_dark.png
	res/drawable-mdpi/ic_switch_video_holo_dark.png
	res/drawable-xhdpi/ic_switch_video_holo_dark.png
	res/layout/call_button_fragment.xml
	src/com/android/incallui/CallButtonFragment.java
Merge github.com:ResurrectionRemix/android_packages_apps_InCallUI into kitkat1