message: dont allocate a payload type for rtp data channels when using sctp
  Cr-Commit-Position: refs/heads/master@{#32651}
diff: @@ -1512,8 +1512,11 @@ std::unique_ptr<SessionDescription> MediaSessionDescriptionFactory::CreateOffer(
  AudioCodecs offer_audio_codecs;
  VideoCodecs offer_video_codecs;
  RtpDataCodecs offer_rtp_data_codecs;
  - GetCodecsForOffer(current_active_contents, &offer_audio_codecs,
  - &offer_video_codecs, &offer_rtp_data_codecs);
  + GetCodecsForOffer(
  + current_active_contents, &offer_audio_codecs, &offer_video_codecs,
  + session_options.data_channel_type == DataChannelType::DCT_SCTP
  + ? nullptr
  + : &offer_rtp_data_codecs);
  if (!session_options.vad_enabled) {
  // If application doesn't want CN codecs in offer.
  StripCNCodecs(&offer_audio_codecs);
  @@ -1930,6 +1933,9 @@ void MediaSessionDescriptionFactory::GetCodecsForOffer(
  // Add our codecs that are not in the current description.
  MergeCodecs<AudioCodec>(all_audio_codecs_, audio_codecs, &used_pltypes);
  MergeCodecs<VideoCodec>(all_video_codecs_, video_codecs, &used_pltypes);
  + // Only allocate a payload type for rtp datachannels when using rtp data
  + // channels.
  + if (rtp_data_codecs)
  MergeCodecs<DataCodec>(rtp_data_codecs_, rtp_data_codecs, &used_pltypes);
  }
  