Add global groupvar to set the ansible async dir

The ansible async directory needs to be defined as something other that
~/.ansible_async to ensure we're not running into selinux violations
when executing tasks with async and become.

Bug: #1861302
Change-Id: I2052aa8861025f8385c0817566fbc37bf6984ac0
Signed-off-by: Kevin Carter <kecarter@redhat.com>

common/services/role.role.j2.yaml

@@ -390,7 +390,10 @@ outputs:
       post_update_tasks: {get_attr: [PostUpdateTasks, value]}
       upgrade_batch_tasks: {get_attr: [UpgradeBatchTasks, value]}
       service_metadata_settings: {get_attr: [ServiceServerMetadataHook, metadata]}
-      ansible_group_vars: {get_attr: [AnsibleGroupVars, value]}
+      ansible_group_vars:
+        map_merge:
+          - ansible_async_dir: "/tmp/.ansible_async"
+          - {get_attr: [AnsibleGroupVars, value]}
       keystone_resources: {get_attr: [KeystoneResourcesConfigs, value]}
 
       # Keys to support docker/services