Use service role with glance service

glance just used to admin role for token validation,
the service role is sufficient for this.

glance also needs an user with enough permission to use swift,
so creating a dedictated service user for swift usage when s-proxy is
enabled.

Change-Id: I6df3905e5db35ea3421468ca1ee6d8de3271f8d1
diff --git a/lib/glance b/lib/glance
index 2d41ea4..00f499a 100644
--- a/lib/glance
+++ b/lib/glance
@@ -124,7 +124,7 @@
     if is_service_enabled s-proxy; then
         iniset $GLANCE_API_CONF DEFAULT default_store swift
         iniset $GLANCE_API_CONF DEFAULT swift_store_auth_address $KEYSTONE_SERVICE_PROTOCOL://$KEYSTONE_SERVICE_HOST:$KEYSTONE_SERVICE_PORT/v2.0/
-        iniset $GLANCE_API_CONF DEFAULT swift_store_user $SERVICE_TENANT_NAME:glance
+        iniset $GLANCE_API_CONF DEFAULT swift_store_user $SERVICE_TENANT_NAME:glance-swift
         iniset $GLANCE_API_CONF DEFAULT swift_store_key $SERVICE_PASSWORD
         iniset $GLANCE_API_CONF DEFAULT swift_store_create_container_on_put True