[VOL-3717] Allowing to pass the olt type via pod-configs yaml file

Change-Id: Ic3873d05d15b40bbbac02eb1d221644a7aaa4c56
(cherry picked from commit 3dcce27449d07e054855b3576e66036924500bdb)
diff --git a/variables/variables.robot b/variables/variables.robot
index 331e6fd..6e82260 100644
--- a/variables/variables.robot
+++ b/variables/variables.robot
@@ -21,3 +21,4 @@
 @{PODLIST1}       voltha-kafka    voltha-ofagent
 @{PODLIST2}       bbsim    etcd-operator-etcd-operator-etcd-operator    radius    voltha-api-server
 ...               voltha-cli-server    voltha-ro-core    voltha-rw-core-11
+${OLT_ADAPTER_APP_LABEL}    adapter-open-olt