OnPlaybackStartRequest
data class OnPlaybackStartRequest(val itemId: UUID, val mediaSourceId: String? = null, val audioStreamIndex: Int? = null, val subtitleStreamIndex: Int? = null, val playMethod: PlayMethod? = null, val liveStreamId: String? = null, val playSessionId: String? = null, val canSeek: Boolean? = false)
Reports that a session has begun playing an item.