Changes to Create a new agent session

added the new optional query request parameter sandbox_by

added the non-success response with the status 409

the response's body type changed from object to no type for status 201

removed the required property agent_name from the response with the 201 status

removed the required property created_at from the response with the 201 status

removed the required property ended_at from the response with the 201 status

removed the required property id from the response with the 201 status

removed the required property metadata from the response with the 201 status

removed the required property org_id from the response with the 201 status

removed the required property sandbox_id from the response with the 201 status

removed the required property started_at from the response with the 201 status

removed the required property status from the response with the 201 status

removed the required property updated_at from the response with the 201 status

added AgentSessionSummary subschema #2 to the response body allOf list for the response status 201