Keyguard: Make sure disabling Camera widget

This fixes the issue that Camera widget is enabled on non-camera devices
until users open up lockscreen settings

Change-Id: I599733f65ec31a16f8a8c5ee98a8a2ba6bc56c63
Merge "Keyguard: Make sure disabling Camera widget" into cm-11.0
Merge remote-tracking branch 'cm/cm-11.0' into cm-11.0-sgt7