fix: setAudioSettings were used instead of setVideoSettings

[Kodam-zz]

Description & motivation

setAudioSettings were used in set videoSettings and set captureSettings, so all videoSettings changes were ignored.

  set videoSettings(VideoSettings videoSettings) {
    assert(_memory != null);
    _videoSettings = videoSettings;
    RtmpStreamPlatform.instance.setAudioSettings( // <- this should to be RtmpStreamPlatform.instance.setVideoSettings(
        {"memory": _memory, "settings": videoSettings.toMap()});
  }

Type of change

• Bug fix (non-breaking change which fixes an issue)

[shogo4405]

Thanks so much!!