message: Add |rids| and |mid| printout to RtpConfig::ToString().
  Cr-Commit-Position: refs/heads/master@{#30726}
diff: @@ -62,7 +62,13 @@ std::string RtpConfig::ToString() const {
  if (i != ssrcs.size() - 1)
  ss << ", ";
  }
  - ss << ']';
  + ss << "], rids: [";
  + for (size_t i = 0; i < rids.size(); ++i) {
  + ss << rids[i];
  + if (i != rids.size() - 1)
  + ss << ", ";
  + }
  + ss << "], mid: '" << mid << "'";
  ss << ", rtcp_mode: "
  << (rtcp_mode == RtcpMode::kCompound ? "RtcpMode::kCompound"
  : "RtcpMode::kReducedSize");
  