RemoteRealtimeMediaSourceProxy should use latest successful constraints when creating the remote source
<rdar://problem/118708700>
Pull request: https://github.com/WebKit/WebKit/pull/20812
Committed 271074@main (6abef0032d2b): <https://commits.webkit.org/271074@main> Reviewed commits have been landed. Closing PR #20812 and removing active labels.