Settings : Make proximity opt-in

Change-Id: Idfa64758a3c6d60ca4801f6f7f34f0429f95cbec
Follow normal lock screen convention - allow user to retry when creating pattern lock

Change-Id: I6ad39b07b8de3de03146322b37b60e3f846093d1
Merge remote-tracking branch 'cm11/cm-11.0' into kitkat