Support L2GW plugin/agent

L2 Gateway (L2GW) is an API framework that offers bridging 2+
networks together to make them look as a single broadcast domain.
A typical use case is bridging the virtual with the physical networks.

Related-Prod: PROD-17614
Change-Id: I4101b94202f87da6f5ecdea75d38dde17f08ca99
diff --git a/metadata/service/control/services/l2gw.yml b/metadata/service/control/services/l2gw.yml
new file mode 100644
index 0000000..75a7ead
--- /dev/null
+++ b/metadata/service/control/services/l2gw.yml
@@ -0,0 +1,7 @@
+applications:
+- neutron
+parameters:
+  neutron:
+    server:
+      l2gw:
+        enabled: true