Disable media controls on known conferencing pages
It can interfere with webcam or microphone and isn't meant to control these anyway. Let's just disable them here instead of trying to chase after all of them.
BUG: 435418 BUG: 435100 BUG: 503965
While media session API nowdays does include callbacks for hangup, webcam, mic, etc, specifically tailored towards video conferencing, our MPRIS stuff is too invasive for tat for now, so let’s finally disable it… I also don’t really have the time rn to investigate/improve, so let’s just disable them.
Rebase of !41 (closed) + MS Teams