Set expanded desktop through profiles (2/2)

Change-Id: I4d79ed61f793fd6a58ad11343be7d5b3d03d9a7e
Add setting for system bars visibility on Keyguard in Expanded desktop mode.

And combine expanded settings into a category.

Change-Id: I8e5a718faae002280da37cdd68e292f01648751b

Conflicts:

	res/xml/system_ui_settings.xml
	src/com/android/settings/cyanogenmod/SystemUiSettings.java