Add openstack_node_role parameter

Add openstack_node_role parameter that will specify node role
primary|secondary. This metadata will be used by formulas as a
trigger to run one-shot operations.

Change-Id: I230590bc5f9d53960c6edaf7e37c44541d9c3342
Related-Prod: PROD-21267
diff --git a/heat/server/single.yml b/heat/server/single.yml
index 0c83206..e686050 100644
--- a/heat/server/single.yml
+++ b/heat/server/single.yml
@@ -9,6 +9,7 @@
           version: latest
   heat:
     server:
+      role: ${_param:openstack_node_role}
       region: ${_param:openstack_region}
       stack_domain_admin:
         name: heat_domain_admin