Make rule_name optional when defining items in openstack_pools
Make rule_name optional when defining items in openstack_pools

Previously it was necessary to provide a value (eventually an
empty string) for the "rule_name" key for each item in
openstack_pools. This change makes that optional and defaults to
empty string when not given.

(cherry picked from commit a83e1aeea39b9c7ae2757b166f3def7d4f67f161)
Signed-off-by: Sébastien Han <62d754cc350e84d3b1c32ae79f976f5348e74a40@redhat.com>

fgal/ceph-ansible,fgal/ceph-ansible