Upstream commit: https://webrtc.googlesource.com/src/+/82364fcc29d07cbf49bbd92c9f920e8334c62b45 RTP Header Extension: record redefinitions and support error return Add UMA histogram "WebRTC.PeerConnection.RtpHeaderExtensionRedefinition" to track how often RTP header extensions are redefined with a different ID. Add field trial "WebRTC-PayloadTypePicker-ErrorOnRtpExtensionRedefinition" to enable returning RTCError::InvalidParameter when such a redefinition occurs. Propagate FieldTrialsView to RtpHeaderExtensionRecorder to support the field trial check. Bug: webrtc:504685269 Change-Id: Ic7a27465c1e08170908b2b49d98494aa6ad96f12 Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/473840 Reviewed-by: Danil Chapovalov <danilchap@webrtc.org> Auto-Submit: Harald Alvestrand <hta@webrtc.org> Commit-Queue: Harald Alvestrand <hta@webrtc.org> Cr-Commit-Position: refs/heads/main@{#47744}