Small fix to the storage sample.
Small fix to the storage sample.

Change-Id: Ia163311da6700c402f9b7f47ec14240c14f89db1

DES157/quickstart-js,uhntiss/quickstart-js,firebase/quickstart-js,DaryaBeda/firebase_,DES157/quickstart-js,uhntiss/quickstart-js,firebase/quickstart-js,DaryaBeda/firebase_,uhntiss/quickstart-js,firebase/quickstart-js