Upgrading to latest ONOS:2.2-latest and latest olt:5.3.0-SNAPSHOT app

Change-Id: I490d40ea8209b683545a01bdd86fea6e63bcdfc1
diff --git a/Dockerfile.voltha-onos b/Dockerfile.voltha-onos
index ae46d70..ef9bdf2 100644
--- a/Dockerfile.voltha-onos
+++ b/Dockerfile.voltha-onos
@@ -34,7 +34,7 @@
 
 
 # Unpack and install specific apps from download stage
-FROM onosproject/onos:2.2.4 as install
+FROM onosproject/onos:2.2-latest as install
 
 # The ENV settings must be replicated below as they are not shared between stages
 ENV ONOS=/root/onos
@@ -58,7 +58,7 @@
 
 
 # Create the final image coping over the installed applications from the install stage
-FROM onosproject/onos:2.2.4
+FROM onosproject/onos:2.2-latest
 
 # The ENV settings must be replicated below as they are not shared between stages
 ENV ONOS=/root/onos