Create router and dhcp when create_default_network set

We are trying to make server SSH-able before detach volume
is performed (details in bug mentioned below). Creating
router and dhcp is needed to setup the proper network path
for server otherwise it fail
- https://zuul.opendev.org/t/openstack/build/04e11a0eac12447f8a3c47fb385b0753

Related-Bug: #1960346

Change-Id: I18eff5a4216d5683a5d49ad0e400ac663650e7a9
diff --git a/tempest/api/compute/base.py b/tempest/api/compute/base.py
index 74601dc..75df5ae 100644
--- a/tempest/api/compute/base.py
+++ b/tempest/api/compute/base.py
@@ -66,7 +66,9 @@
         # Setting network=True, subnet=True creates a default network
         cls.set_network_resources(
             network=cls.create_default_network,
-            subnet=cls.create_default_network)
+            subnet=cls.create_default_network,
+            router=cls.create_default_network,
+            dhcp=cls.create_default_network)
         super(BaseV2ComputeTest, cls).setup_credentials()
 
     @classmethod