Resolve the issue where serviceWorkers do not have access to runtime arg...

...uments.

Resolves: https://issues.cask.co/browse/CDAP-969

The resolution is a one-line change, but to ensure that this feature does not get lost in the future, I have changed an existing test case to utilize the feature.

Bamboo: https://builds.cask.co/browse/CDAP-RBT37