Adding netconf secret for adtran openolt adapter

Change-Id: I39596ef81d89c27ee17f92e3e09819d8bddf69d6
diff --git a/kubernetes-configs/voltha/dt-berlin-pod-gpon-adtran.yml b/kubernetes-configs/voltha/dt-berlin-pod-gpon-adtran.yml
index 96ad1f3..865de76 100644
--- a/kubernetes-configs/voltha/dt-berlin-pod-gpon-adtran.yml
+++ b/kubernetes-configs/voltha/dt-berlin-pod-gpon-adtran.yml
@@ -28,6 +28,9 @@
     repository: "voltha-adtran-adapter"
     tag: "1.4.0"
 
+network:
+  netconfUserSecret: ''
+
 
 deployments:
   etcdOperator: true