https://wpt.fyi/results/mst-content-hint/RTCRtpSendParameters-degradationEffect.html shows that degradationPreference is not unset initially
<rdar://problem/116454410>
Pull request: https://github.com/WebKit/WebKit/pull/18616
Committed 268911@main (455093e80956): <https://commits.webkit.org/268911@main> Reviewed commits have been landed. Closing PR #18616 and removing active labels.