The two-way audio session in <TalkConfig>.
optional
duplex: "FDX" | "HDX"
Full or half duplex.
optional
audioStreamMode: "followVideoStream" | "onlyAudioStream" | "mixAudioStream"
Whether talk audio rides the video stream, its own stream, or a mix.
mixAudioStream is Video Doorbell PoE only.
optional
audioConfig: TalkAudioConfig
The audio format.