Bug 1072500 - Do not launch FindMyDevice when user triggers Camera from LockScreen

When the user triggers Camera from the LockScreen, FMD will catch the
event and wake up. This consumes a preallocated process at least.
Figures shows that we double the launch time from the Camera app point
of view.
Merge pull request #25034 from lissyx/bug1072500

Bug 1072500 - Do not launch FindMyDevice when user triggers Camera from LockScreen r=kgrandon