Add possibility to manage file permissions of config files.

Fixes-bug: PROD-36552
Change-Id: If346c0996b4ab957edc02b56fbaebda2fa671ab6
diff --git a/metadata/service/server/single.yml b/metadata/service/server/single.yml
index 1099077..2880e65 100644
--- a/metadata/service/server/single.yml
+++ b/metadata/service/server/single.yml
@@ -2,6 +2,7 @@
 - barbican
 classes:
 - service.barbican.support
+- service.barbican.file_permissions
 parameters:
   _param:
     openstack_log_appender: false