VOL-4268: Migrate to BAL3.4.9.9 for voltha-2.8 release

Change-Id: I4ad88e7aae992856b1b127902cff6e19a05e4314
diff --git a/deployment-configs/dt-berlin-pod-gpon-DT.yaml b/deployment-configs/dt-berlin-pod-gpon-DT.yaml
index 2b3195b..a9779e4 100644
--- a/deployment-configs/dt-berlin-pod-gpon-DT.yaml
+++ b/deployment-configs/dt-berlin-pod-gpon-DT.yaml
@@ -56,7 +56,7 @@
       fortygig: False
       aggPort: 2
       serial: EC1912001814
-      oltDebVersion: openolt_asgvolt64-3.4.8-eec0fc9e9a01dc0d35b0b8441e0a22a4c0cc51b4-100G-NNI.deb
+      oltDebVersion: openolt_asgvolt64-3.4.9-e2a9597f3d690fe3a0ea0df244571dfc9e8c2833-100G-NNI.deb
       board_technology: GPON
  
   hosts: