Changes to Job-wide Auto Tune backoff/notification config

removed the optional property backoff_policy/cold_start_threshold_pct from the response with the 200 status

removed the optional property backoff_policy/cold_start_threshold_per_day from the response with the 200 status

removed the optional property backoff_policy/restarts_after_shutdown from the response with the 200 status

removed the optional property backoff_policy/stability_period_days from the response with the 200 status

removed the optional property backoff_policy/trigger_action from the response with the 200 status

added the optional property backoff_policy/latency_threshold_pct to the response with the 200 status

endpoint added