Move ceph_admin_extra_vars logic to tripleo-ansible

Instead of creating ceph_admin_extra_vars with
distribute_private_key always set to true, set
that variable to true only when appropriate based
on logic in the depends-on patch.

Also, it is not necessary to override the values of
tripleo_admin_generate_key or ssh_servers to create
the ceph-admin user for cephadm.

Related-Bug: #1928717
Depends-On: I8343c419c140670f01bdc94b4c8130004bac64e1
Change-Id: I2bacf82f85e5c78f5ae603460919cf3ff7130e9c
(cherry picked from commit 9fb6b36f14)

deployment/cephadm/ceph-base.yaml

@@ -579,18 +579,6 @@ outputs:
                             ms_client_mode: secure
                       - {get_attr: [DefaultCephConfigOverrides, value, vars]}
                 cephadm_extra_vars: {get_attr: [CephAdmVars, value, vars]}
-                ceph_admin_extra_vars:  # user creation
-                  tripleo_admin_generate_key: false
-                  distribute_private_key: true
-                  tripleo_admin_user: ceph-admin
-                  ssh_servers: "{{ groups['ceph_mon'] |
-                                   union(groups['ceph_osd']|default([])) |
-                                   union(groups['ceph_mgr']|default([])) |
-                                   union(groups['ceph_rgw']|default([])) |
-                                   union(groups['ceph_mds']|default([])) |
-                                   union(groups['ceph_nfs']|default([])) |
-                                   union(groups['ceph_rbdmirror']|default([])) |
-                                   unique }}"
             - name: Prepare cephadm user and keys
               include_role:
                 name: tripleo_run_cephadm