Changes to Start audio playback to a leg

the request property mime_type became required

the request property tone became required

the request property url became required

removed the required property playback_id from the response with the 200 status

the request property repeat with a default value became required

the request property volume with a default value became required

the request property mime_type became optional

the request property repeat became optional

the request property tone became optional

the request property url became optional

the request property volume became optional

added the required property playback_id to the response with the 200 status

the request property mime_type became required

the request property tone became required

the request property url became required

removed the required property playback_id from the response with the 200 status

the request property repeat with a default value became required

the request property volume with a default value became required