Installer: quote password where it applies

Prior to this change, password having shell interpretable character
would break the installer (e.g '&', '(', etc... )

This commits rely on the `quote` filter from ansible to ensure those
password are properly quoted where it applies

Fixes: https://github.com/ansible/awx/issues/3943
Signed-off-by: Yanis Guenane <yguenane@redhat.com>

installer/roles/kubernetes/tasks/backup.yml

@@ -49,7 +49,7 @@
 - name: Dump database
   shell: |
     {{ kubectl_or_oc }} -n {{ kubernetes_namespace }} exec ansible-tower-management -- \
-      bash -c "PGPASSWORD={{ pg_password }} \
+      bash -c "PGPASSWORD={{ pg_password | quote }} \
         pg_dump --clean --create \
           --host='{{ pg_hostname | default('postgresql') }}' \
           --port={{ pg_port | default('5432') }} \