Fix ironic gate

This patch fixes a few minor issues:
* The ironic_service_user_name was not being passed to Nova
  - this value was fixed in Nova #1647253
* The br-flat network seems to already existing on some gate nodes, this
has been changed to named br-vlan

Change-Id: I12f68a1cda39a3d615fbcf6ad62694faca6d09f4

tests/host_vars/localhost.yml

@@ -21,7 +21,7 @@ bridges:
     ip_addr: "10.1.1.1"
   - name: "br-vxlan"
     ip_addr: "10.1.2.1"
-  - name: "br-flat"
+  - name: "br-vlan"
     ip_addr: "10.1.3.1"
     veth_peer: "eth12"
   - name: "br-ipmi"

tests/host_vars/openstack1.yml

@@ -45,7 +45,7 @@ container_networks:
     netmask: null
     type: "veth"
   flat_address:
-    bridge: "br-flat"
+    bridge: "br-vlan"
     interface: "eth12"
     netmask: null
     type: veth

tests/os_ironic-overrides.yml

@@ -36,3 +36,4 @@ ironic_neutron_provisioning_network_name: "ironic-prov"
 neutron_l3: True
 neutron_metadata: True
 ironic_pip_package_state: latest
+ironic_service_user_name: "ironic"