Fix ansible-lint error 502 (unnamed-task) for example playbooks.

This patch adds 'name' to all example playbook tasks that did not
have it, fixing ansible-lint's error 'unnamed-task'.

playbooks/vault/retrive-data-symmetric-vault.yml

@@ -14,5 +14,6 @@
         state: retrieved
       register: result
       no_log: true
-    - debug:
-        msg: "{{ result.vault.data }}"
+    - name: Display retrieved data.
+      debug:
+        msg: "Data: {{ result.vault.data }}"