Release WebRTC remote encoder/decoder callback lock right after having the changed the callback
<rdar://74560516>
Created attachment 425250 [details] Patch
Created attachment 425254 [details] Patch
Created attachment 425256 [details] Patch
Committed r275525: <https://commits.webkit.org/r275525> All reviewed patches have been landed. Closing bug and clearing flags on attachment 425256 [details].