Policy.json should be defined by user

User can override and add values to policy.json by creating flat
key-value structure under cinder:controller:policy.

Change-Id: I1d58c632442cd1ffb19f2020ab9e5e63bea975a9
diff --git a/tests/pillar/ceph_single.sls b/tests/pillar/ceph_single.sls
index 79838a2..d996ad2 100644
--- a/tests/pillar/ceph_single.sls
+++ b/tests/pillar/ceph_single.sls
@@ -40,6 +40,9 @@
       name: cinder
       user: cinder
       password: pwd
+    policy:
+      'volume:delete': 'rule:admin_or_owner'
+      'volume:extend':
   volume:
     enabled: true
     version: liberty