pollInterval Parameter support added

Change-Id: Ia13a8e4d1d1296f3c79bd5610603f8e1fc5f537e
diff --git a/jjb/pipeline/voltha-scale-measurements.groovy b/jjb/pipeline/voltha-scale-measurements.groovy
index 0239627..025eb75 100644
--- a/jjb/pipeline/voltha-scale-measurements.groovy
+++ b/jjb/pipeline/voltha-scale-measurements.groovy
@@ -75,7 +75,7 @@
           until [ $i -eq $onuTarget ]
           do
             echo "$i ONUs ACTIVE of $onuTarget expected (time: $SECONDS)"
-            sleep 20
+            sleep $pollInterval
             i=$(voltctl device list | grep -v OLT | grep ACTIVE | wc -l)
           done
           echo "$onuTarget ONUs Activated in $SECONDS seconds (time: $SECONDS)"