Use dogtag backend for barbican on virt envs

Change-Id: I3282d16e4606ae97f2d7cae1780f2e1f0d8f143b
diff --git a/tcp_tests/templates/heat-cicd-queens-dvr-sl/salt-context-cookiecutter.yaml b/tcp_tests/templates/heat-cicd-queens-dvr-sl/salt-context-cookiecutter.yaml
index 1614be8..976e782 100644
--- a/tcp_tests/templates/heat-cicd-queens-dvr-sl/salt-context-cookiecutter.yaml
+++ b/tcp_tests/templates/heat-cicd-queens-dvr-sl/salt-context-cookiecutter.yaml
@@ -313,6 +313,7 @@
   #openstack_public_neutron_subnet_allocation_end: 172.17.16.245
   manila_enabled: 'False'
   barbican_enabled: 'True'
+  barbican_backend: dogtag
   barbican_integration_enabled: 'False'
 
   openstack_barbican_address: 10.167.4.44