Don't recreate the audio receive stream when updating the local_ssrc.

Bug: webrtc:11993
Change-Id: Ic5d8a8a8b7c12fb1d906e0b3cbdf657fd9e8eafc
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/222042
Commit-Queue: Tommi <tommi@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#34299}

modules/rtp_rtcp/source/rtp_rtcp_interface.h

@@ -180,6 +180,10 @@ class RtpRtcpInterface : public RtcpFeedbackSenderInterface {
 
   virtual void SetRemoteSSRC(uint32_t ssrc) = 0;
 
+  // Called when the local ssrc changes (post initialization) for receive
+  // streams to match with send. Called on the packet receive thread/tq.
+  virtual void SetLocalSsrc(uint32_t ssrc) = 0;
+
   // **************************************************************************
   // Sender
   // **************************************************************************