[VOL-4355] Fixed hardcoded namespace values

Change-Id: I90894ab10ddcb57d9b59123479240fc9c3c7d967
diff --git a/tests/pm-data/Voltha_ONUPMTests.robot b/tests/pm-data/Voltha_ONUPMTests.robot
index 4346925..b3d3151 100755
--- a/tests/pm-data/Voltha_ONUPMTests.robot
+++ b/tests/pm-data/Voltha_ONUPMTests.robot
@@ -45,7 +45,8 @@
 
 
 *** Variables ***
-${namespace}      voltha
+${NAMESPACE}      voltha
+${INFRA_NAMESPACE}      default
 ${timeout}        60s
 ${of_id}          0
 ${logical_id}     0