message: video_replay: add AV1 support to IVF filewriter
  which is already supported in modules/video_coding/utility/ivf_file_reader.cc
  Cr-Commit-Position: refs/heads/main@{#37390}
diff: @@ -290,6 +290,8 @@ class DecoderIvfFileWriter : public test::FakeDecoder {
  video_codec_type_ = VideoCodecType::kVideoCodecVP9;
  } else if (codec == "H264") {
  video_codec_type_ = VideoCodecType::kVideoCodecH264;
  + } else if (codec == "AV1") {
  + video_codec_type_ = VideoCodecType::kVideoCodecAV1;
  } else {
  RTC_LOG(LS_ERROR) << "Unsupported video codec " << codec;
  RTC_DCHECK_NOTREACHED();
  