The wss://…/telephony/vonage/media endpoint to connect the inbound call's audio to.
OptionalcontentType: stringOptional wire content-type (defaults to audio/l16;rate=8000).
The NCCO document (a JSON array) to return to Vonage as the answer-webhook response.
The NCCO returned to an inbound call's answer webhook to connect its bidirectional WebSocket media leg. Identical
connectwebsocket shape as the outbound path (it reuses buildConnectNcco), so inbound and outbound legs share one media contract.