Ignore the monasca_thresh container if it is listed as exited.
The container was recently changed to operate as a 'one shot' container,
submitting a job to storm then exiting. This does not fit with the
usual pattern of Kolla Ansible container usage, but is harmless.

Depends-On: https://review.opendev.org/c/openstack/kolla/+/811977

Change-Id: Id40d2260a67ef604255fb1818d41cdcbc73164d7