Generate random keystone users

Change-Id: I8dbd07b10d29b43d1c35fa76bcaa0f0efb32beda
Related-Prod: PROD-29868
diff --git a/ironic/conductor/storage/cinder.yml b/ironic/conductor/storage/cinder.yml
index 33af09a..22dc687 100644
--- a/ironic/conductor/storage/cinder.yml
+++ b/ironic/conductor/storage/cinder.yml
@@ -11,5 +11,5 @@
         project_domain_id: default
         project_name: service
         user_domain_name: Default
-        username: cinder
+        username: ${_param:keystone_cinder_username}
         region: ${_param:openstack_region}