Policy.json should be defined by user

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

Change-Id: I4db6b17ab1ff925aa20cd3565417a4b35ed4561e
diff --git a/tests/pillar/single_multiple_backends.sls b/tests/pillar/single_multiple_backends.sls
index 4a9d6a2..3ca1e4e 100644
--- a/tests/pillar/single_multiple_backends.sls
+++ b/tests/pillar/single_multiple_backends.sls
@@ -68,3 +68,6 @@
           ssl_compression: false
           use_trusts: false
           user: 2ec7966596504f59acc3a76b3b9d9291:glance-project
+    policy:
+      publicize_image: "role:admin"
+      add_member: