Use symlink link_type for ODCS in staging

roles/odcs/base/templates/etc/odcs/raw_config_wrapper.conf.j2

@@ -12,3 +12,9 @@ createrepo_deltas = False
 # In runroot, we cannot use guestmount, but have to use mount -o loop.
 buildinstall_use_guestmount=False
 
+# We cannot use hardlinks on stg, because it uses different volume and copy
+# just takes lot of storage.
+{% if env == 'staging' %}
+link_type = 'symlink'
+{% endif %}
+