Correct timer units to seconds from milliseconds. (#27360)
Correct timer units to seconds from milliseconds. (#27360)

``dagrun.duration.success.<dag_id>``
``dagrun.schedule_delay.<dag_id>``
``dagrun.<dag_id>.first_task_scheduling_delay`` are reported to statsd in seconds, not milliseconds. Other timers in this list might be suspect, but I haven't checked them yet.
apache/airflow,apache/airflow,apache/airflow,apache/airflow,apache/airflow,apache/airflow