Enable DHCP for dynamic subnets for test

Related-Prod: PRODX-26471
Change-Id: I448c6a4b2ae017118137f7081c269274bcf6d05e
diff --git a/barbican_tempest_plugin/tests/scenario/manager.py b/barbican_tempest_plugin/tests/scenario/manager.py
index 28b19e3..fae7518 100644
--- a/barbican_tempest_plugin/tests/scenario/manager.py
+++ b/barbican_tempest_plugin/tests/scenario/manager.py
@@ -41,7 +41,9 @@
 
     @classmethod
     def setup_credentials(cls):
-        cls.set_network_resources(network=True, subnet=True, router=True)
+        cls.set_network_resources(
+            network=True, subnet=True, router=True, dhcp=True
+        )
         super().setup_credentials()
 
     @classmethod