[fenix] For https://github.com/mozilla-mobile/fenix/issues/27228 - Resume qr scanning if camera permission is changed
If permissions are changed the app process is restarted with the same
happening for the previously running app components.
SearchDialogFragment used for searches will check if qr scanning was in
progress and resume if needed.
PairFragment used for signing-in will start scanning on itself.
Android-Components will avoid resuming the scan functionality if the camera
permission is missing and so allow to request the permission again without the
camera permission related system calls causing issues.