Supports two scenarios:
1) variables defined in defaults/main.yml are sufficient to create
a root/intermediate CA certificate for mariadb when this role
is used outside openstack-ansible.
2) when:
openstack_pki_dir
openstack_pki_setup_host
openstack_pki_authorities
openstack_pki_service_intermediate_cert_name
are defined, an external CA already created on the deploy host
with a previous run of ansible-role-pki will be used as the CA.
Server certificates for the galera instances are created from the
data in galera_pki_certificates in both situations
Depends-On: https://review.opendev.org/c/openstack/ansible-role-pki/+/807771
Change-Id: I72738e4f8bd2233dedbed4428baafd4436de84b5
6bc6929d09