Wait keystone_fernet running before init tokens

Init fernet task fails if keystone_fernet container
is not running and ssh port bind.
This change add a check to ensure all keystone_fernet containers
are running before init fernet tokens.

Change-Id: Ib95bb5a47a9174f1a00b82cc8b697c0dc19c848e
Closes-Bug: #1704758

ansible/roles/keystone/tasks/init_fernet.yml

 ---
+- name: Waiting for Keystone SSH port to be UP
+  wait_for:
+    host: "{{ api_interface_address }}"
+    port: "{{ keystone_ssh_port }}"
+    connect_timeout: 1
+  register: check_keystone_ssh_port
+  until: check_keystone_ssh_port | success
+  retries: 10
+  delay: 5
+
 - name: Initialise fernet key authentication
   command: "docker exec -t keystone_fernet kolla_keystone_bootstrap {{ keystone_username }} {{ keystone_groupname }}"
   register: fernet_create