Remove excessive log spam from receiver.getParameters().

It's normal for a receiver to not be configured to receive, such as when
currentDirection is not (or not yet) "sendrecv" or "recvonly".
getParameters() returning an empty set of encodings is valid and these
logs are not very useful. It's also inconsistent that we only log after
SLD has happened due to different code paths inside getParameters(),
repro: https://jsfiddle.net/henbos/xqksj3wd/.

Most notably we're calling getParameters() internally from inside of
getStats() which can cause excessive log spam. I prefer that we remove
these logs rather than avoid calling getParameters() from inside of
getStats() on non-receiving receivers since it's valid to check how many
encodings exist on a receiver using getParameters(), and whether or not
the SSRC has been signaled could in theory affect the number of
encodings even if we do want to receive. Also an app calling
getParameters() on an inactive receiver is valid and should not cause
logs.

Bug: webrtc:14225
Change-Id: I4290781d6aed92aa03fe0c662762aa97c99a045c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/266960
Commit-Queue: Erik Språng <sprang@webrtc.org>
Auto-Submit: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37335}

media/engine/webrtc_video_engine.cc

@@ -1157,9 +1157,9 @@ webrtc::RtpParameters WebRtcVideoChannel::GetDefaultRtpReceiveParameters()
   RTC_DCHECK_RUN_ON(&thread_checker_);
   webrtc::RtpParameters rtp_params;
   if (!default_unsignalled_ssrc_handler_.GetDefaultSink()) {
-    RTC_LOG(LS_WARNING) << "Attempting to get RTP parameters for the default, "
-                           "unsignaled video receive stream, but not yet "
-                           "configured to receive such a stream.";
+    // Getting parameters on a default, unsignaled video receive stream but
+    // because we've not configured to receive such a stream, `encodings` is
+    // empty.
     return rtp_params;
   }
   rtp_params.encodings.emplace_back();

media/engine/webrtc_voice_engine.cc

@@ -1479,9 +1479,9 @@ webrtc::RtpParameters WebRtcVoiceMediaChannel::GetDefaultRtpReceiveParameters()
   RTC_DCHECK_RUN_ON(worker_thread_);
   webrtc::RtpParameters rtp_params;
   if (!default_sink_) {
-    RTC_LOG(LS_WARNING) << "Attempting to get RTP parameters for the default, "
-                           "unsignaled audio receive stream, but not yet "
-                           "configured to receive such a stream.";
+    // Getting parameters on a default, unsignaled audio receive stream but
+    // because we've not configured to receive such a stream, `encodings` is
+    // empty.
     return rtp_params;
   }
   rtp_params.encodings.emplace_back();