ES6 fix to the instagram sample
ES6 fix to the instagram sample

Change-Id: I74487e1490f9c155eb3b372b96ce56e4a189441d

Kevded/functions-samples,firebase/functions-samples,firebase/functions-samples,firebase/functions-samples,Kevded/functions-samples,Kevded/functions-samples,Kevded/functions-samples,firebase/functions-samples