Move frame drop config to VideoCodec and VideoEncoderConfig.

Intend to delete corresponding codec-specific settings in a followup.

Bug: webrtc:6883
Change-Id: I78ab07729a5aee1055f80d39d8f7289beb6721e1
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/262244
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36882}

modules/video_coding/video_codec_initializer.cc

@@ -72,6 +72,7 @@ VideoCodec VideoCodecInitializer::VideoEncoderConfigToVideoCodec(
       config.content_type == VideoEncoderConfig::ContentType::kScreen &&
       config.legacy_conference_mode;
 
+  video_codec.SetFrameDropEnabled(config.frame_drop_enabled);
   video_codec.numberOfSimulcastStreams =
       static_cast<unsigned char>(streams.size());
   video_codec.minBitrate = streams[0].min_bitrate_bps / 1000;