Bug 849718 - [LockScreen] Don't prompt for SIM PIN when opening lockscreen camera. r=timdream

Extended custom event 'unlock' with origin detail ({ areaCamera: true }) when dispatching
it from the camera unlock button.
Merge pull request #9160 from mcirlanaru/bug_849718

Bug 849718 - Don't prompt for SIM PIN when opening lock screen camera, r=@timdream