For consistency with the new --display-orientation option, express the
--lock-video-orientation in degrees clockwise:
* --lock-video-orientation=0 -> --lock-video-orientation=0
* --lock-video-orientation=3 -> --lock-video-orientation=90
* --lock-video-orientation=2 -> --lock-video-orientation=180
* --lock-video-orientation=1 -> --lock-video-orientation=270