message: Propagate scalability mode in CreateSimulcastOrConferenceModeScreenshareStreams.
  Cr-Commit-Position: refs/heads/main@{#35178}
diff: @@ -3692,6 +3692,8 @@ EncoderStreamFactory::CreateSimulcastOrConferenceModeScreenshareStreams(
  for (size_t i = 0; i < layers.size(); ++i) {
  layers[i].active = encoder_config.simulcast_layers[i].active;
  + layers[i].scalability_mode =
  + encoder_config.simulcast_layers[i].scalability_mode;
  // Update with configured num temporal layers if supported by codec.
  if (encoder_config.simulcast_layers[i].num_temporal_layers &&
  IsTemporalLayersSupported(codec_name_)) {
  