Backport of "webrtcbin: Avoid access of freed memory" into 1.20
requested to merge tpm/gstreamer:backport-mr-2256-into-1.20-webrtcbin_fix_memory_access_after_free into 1.20
Backport of !2256 (merged) "webrtcbin: Avoid access of freed memory".
Commits:
- 72907800 webrtcbin: Avoid access of freed memory