Expose User interface only on selected devices

Signed-off-by: Paul Beeler <sparksco@gmail.com>

Conflicts:
	src/com/android/settings/saber/SystemSettings.java
Show preference for NavRing only on USER_OWNER
Signed-off-by: Paul Beeler <sparksco@gmail.com>
About nexus
Signed-off-by: Paul Beeler <sparksco@gmail.com>
derp
Signed-off-by: Paul Beeler <sparksco@gmail.com>