Properly propagate error in WebRtcVideoSendStream::SetRtpParameters

When an error occurs, the callback needs to be invoked or the
signaling thread may block indefinitely waiting for it.

Bug: webrtc:15871
Change-Id: Ib73382aff07b3632794300985223c70c24f554f4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/342901
Reviewed-by: Florent Castelli <orphis@webrtc.org>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Commit-Queue: Ilya Nikolaevskiy <ilnik@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#41904}

media/engine/webrtc_video_engine.cc

@@ -1966,8 +1966,7 @@ WebRtcVideoSendChannel::WebRtcVideoSendStream::SetRtpParameters(
   webrtc::RTCError error = CheckRtpParametersInvalidModificationAndValues(
       rtp_parameters_, new_parameters);
   if (!error.ok()) {
-    // Error is propagated to the callback at a higher level
-    return error;
+    return webrtc::InvokeSetParametersCallback(callback, error);
   }
 
   bool new_param = false;