Add tripleo_delegate_to var for ceph health validation
Add tripleo_delegate_to var for ceph health validation

According to the tripleo-validation change, we're just
moving from the default ansible delegate_to to the
tripleo_delegate_to directive provided by TripleO.
This ensure the task is executed using the overcloud
facts, fixing the upgrade (from queens) scenario.

Depends-On: https://review.opendev.org/718011
Closes-Bug: #1871380
Change-Id: I08e44544e1069c5fd1b2d9832c6778ff32427369

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates