Set 022 umask for image files in salt control

PROD-28442

Change-Id: Ia5907f3d48965a44e1a08ac845ee313433ac81b5
diff --git a/salt/control/virt.yml b/salt/control/virt.yml
index 8f599bd..3cd93d8 100644
--- a/salt/control/virt.yml
+++ b/salt/control/virt.yml
@@ -5,6 +5,7 @@
     control:
       enabled: True
       virt_enabled: True
+      file_mask: 022
   virt:
     nic:
       default: