Add --user-domain when adding heat role admin

The --user-domain parameter is required when adding the role for
Heat.  Without it, the command fails and the bootstrap
container exits early with the error message:

"No user with a name or ID of 'heat_domain_admin' exists."

Change-Id: I6f813edde3f437bca3ef521a43454146082bc5f5
Closes-bug: #1611768
Signed-off-by: Dave Walker (Daviey) <email@daviey.com>

docker/heat/heat-api/extend_start.sh

@@ -9,7 +9,7 @@ if [[ "${!KOLLA_BOOTSTRAP[@]}" ]]; then
     if [[ "heat_user_domain" != "$CURRENT_HEAT_DOMAIN_NAME" ]]; then
         openstack domain create heat_user_domain
         openstack user create --domain heat_user_domain heat_domain_admin --password ${HEAT_DOMAIN_ADMIN_PASSWORD}
-        openstack role add --domain heat_user_domain --user heat_domain_admin admin
+        openstack role add --domain heat_user_domain --user-domain heat_user_domain --user heat_domain_admin admin
         openstack role create heat_stack_owner
         openstack role create heat_stack_user
     fi