Backport of "webrtcbin: also add rtcp-fb ccm fir for video mlines by default" into 1.20
Backport of !3235 (merged) "webrtcbin: also add rtcp-fb ccm fir for video mlines by default".
Commits:
- a633f5d2 webrtcbin: also add rtcp-fb ccm fir for video mlines by default