External streams APIs

Number of APIs: 5

1. Start external stream for a room POST {{HOST}}/v2/external-streams/room/:room_id/start

2. Stop external stream for a room POST {{HOST}}/v2/external-streams/room/:room_id/stop

3. Stop external stream by id POST {{HOST}}/v2/external-streams/:stream_id/stop

4. Get all external streams GET {{HOST}}/v2/external-streams

5. Get external stream GET {{HOST}}/v2/external-streams/:stream_id