Create public router and enable dhcp for heat subnet

Fix for test_server_cfn_init and test_create_stack_with_multi_signal_waitcondition
Related-PROD: PROD-19771, PROD-19827

Change-Id: I3dc18046fdf53ffce84237fa502bc2001a6b59ae
diff --git a/metadata/service/tempest/neutron.yml b/metadata/service/tempest/neutron.yml
index 1d571dc..de5f303 100644
--- a/metadata/service/tempest/neutron.yml
+++ b/metadata/service/tempest/neutron.yml
@@ -3,6 +3,13 @@
     client:
       server:
         admin_identity:
+          router:
+            heat-router:
+              tenant: admin
+              admin_state_up: True
+              gateway_network: ${_param:runtest_tempest_public_net}
+              interfaces:
+                - heat_subnet
           network:
             heat-net:
               tenant: admin
@@ -16,4 +23,4 @@
                     - start: 10.20.30.10
                       end: 10.20.30.254
                   gateway: 10.20.30.1
-                  enable_dhcp: False
\ No newline at end of file
+                  enable_dhcp: True