[VOL-4237] Keep log files unless is set to false

Change-Id: Ifabea307105ea532cecbd38e37cf5ebe057c61b3
diff --git a/tests/software-upgrades/ONU_Upgrade.robot b/tests/software-upgrades/ONU_Upgrade.robot
index 2fa442c..bfd1eab 100755
--- a/tests/software-upgrades/ONU_Upgrade.robot
+++ b/tests/software-upgrades/ONU_Upgrade.robot
@@ -57,6 +57,10 @@
 
 ${suppressaddsubscriber}    True
 
+# logging flag to enable Collect Logs, can be passed via the command line too
+# example: -v logging:False
+${logging}    True
+
 # ONU Image to test for Upgrade needs to be passed in the following format:
 ${image_version}    ${EMPTY}
 # Example value: BBSM_IMG_00002