[RTCRtpTransceiver-stop.html]
[If a transceiver is stopped, transceivers should end up in state stopped]
bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1568296
expected: FAIL
[If a transceiver is stopped, transceivers, senders and receivers should disappear after offer/answer]
bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1568296
expected: FAIL