Use include_role in task to avoid lack of access to vars

This patch updates the security hardening playbook to use include_role
within a task versus using 'roles' directly to fix cases where
apply_security_hardening is set to False. Some change to Ansible
appears to limit access to vars when the role is skipped, resulting
in failures. The side effect of this change is the role is skipped
entirely (when applicable) versus the individual tasks being skipped,
which speeds up deployment times.

Change-Id: Iaf81f778ffd9fcf6572e03e8ce73ffef46bd98aa

playbooks/infra-journal-remote.yml

@@ -22,7 +22,9 @@
 - name: Install Journal-Remote
   hosts: hosts
   gather_facts: false
-  roles:
-    - openstack.osa.journald_remote
+  tasks:
+    - name: Include journald-remote role
+      include_role:
+        name: openstack.osa.journald_remote
   tags:
     - journal-remote

playbooks/security-hardening.yml

@@ -35,8 +35,10 @@
   gather_facts: false
   user: root
   pre_tasks:
-  roles:
-    - role: "ansible-hardening"
+  tasks:
+    - name: Include security hardening role
+      include_role:
+        name: "ansible-hardening"
       when: apply_security_hardening | bool
   environment: "{{ deployment_environment_variables | default({}) }}"
   tags: