[VOL-4355] Fixed hardcoded namespace values

Change-Id: I90894ab10ddcb57d9b59123479240fc9c3c7d967
diff --git a/tests/bbsim/Voltha_BBSimTests.robot b/tests/bbsim/Voltha_BBSimTests.robot
index c29b2cc..47643ba 100755
--- a/tests/bbsim/Voltha_BBSimTests.robot
+++ b/tests/bbsim/Voltha_BBSimTests.robot
@@ -34,6 +34,7 @@
 
 *** Variables ***
 ${NAMESPACE}      voltha
+${INFRA_NAMESPACE}      default
 ${timeout}        60s
 ${of_id}          0
 ${logical_id}     0