Do not collect physical host facts in playbook

The role itself depends on physical host facts being collected,
but the collection occurring in the playbook does not accommodate
--limit containername, it will require
--limit containername:physicalhost in order for the required facts
to be collected.

To allow limit to target only the containers being created, the
fact collection has been moved to the role and the module is
executed against the physical_host using delegation.

Depends-On: https://review.openstack.org/#/c/554105/
Change-Id: Idc0ae7913b3ea9374caa41a207fab8c72f42bf41

playbooks/containers-lxc-create.yml

@@ -13,10 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-- name: Gather lxc container host facts
-  hosts: "{{ lxc_host_group | default('lxc_hosts') }}"
-  gather_facts: "{{ osa_gather_facts | default(True) }}"
-
 - name: Set lxc containers group
   hosts: "{{ container_group | default('all_containers') }}"
   gather_facts: false