Using openolt-adapter 2.5.6 and voltha-onos 4.1.6 in voltha-2.5 release

Change-Id: I14da3dad71f5cc79cc3c419f45469fa615ced53f
diff --git a/releases/voltha-2.5 b/releases/voltha-2.5
index c09c2c8..22c0fe2 100644
--- a/releases/voltha-2.5
+++ b/releases/voltha-2.5
@@ -5,7 +5,7 @@
 
 export VOLTHA_CHART_VERSION=2.6.1
 export VOLTHA_BBSIM_CHART_VERSION=4.0.0
-export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.6.2
+export VOLTHA_ADAPTER_OPEN_OLT_CHART_VERSION=2.6.3
 export VOLTHA_ADAPTER_OPEN_ONU_CHART_VERSION=2.5.0
 export ONOS_CLASSIC_CHART_VERSION=0.1.8
 export RADIUS_CHART_VERSION=1.0.1
@@ -18,4 +18,4 @@
 # kind-voltha's default which is 'master'.
 # Also we need to specify the tag for voltha/voltha-onos image since this is
 # not in the ONOS chart.
-export EXTRA_HELM_FLAGS="--set defaults.image_tag=null,images.onos.tag=4.1.5 "
+export EXTRA_HELM_FLAGS="--set defaults.image_tag=null,images.onos.tag=4.1.6 "