rbd-mirror: Allow to copy the admin keyring

The ceph-rbd-mirror role allows to copy the admin keyring via the
copy_admin_key variable but there's actually no task in that role
doing the job.

Signed-off-by: Dimitri Savineau <dsavinea@redhat.com>
(cherry picked from commit 1f505628dd)

roles/ceph-rbd-mirror/tasks/common.yml

@@ -7,4 +7,15 @@
     group: "{{ ceph_uid if containerized_deployment else 'ceph' }}"
     mode: "{{ ceph_keyring_permissions }}"
   when:
-    - cephx
+    - cephx
+
+- name: copy ceph admin keyring if needed
+  copy:
+    src: "{{ fetch_directory }}/{{ fsid }}/etc/ceph/{{ cluster }}.client.admin.keyring"
+    dest: "/etc/ceph/{{ cluster }}.client.admin.keyring"
+    owner: "{{ ceph_uid if containerized_deployment else 'ceph' }}"
+    group: "{{ ceph_uid if containerized_deployment else 'ceph' }}"
+    mode: "{{ ceph_keyring_permissions }}"
+  when:
+    - cephx | bool
+    - copy_admin_key | bool