I've been researching this for almost a week now, and I feel more confused now than when I started. I realize that the QVSource is the recommended plugin, but it's out of the budget.
I have been able to connect the rest connector to our google analytics, but when I go to load the data, nothing shows up other than the dimensions and metrics I've chosen (ie.. "ga:sessions", "ga:country" etc).
I had a long discussion with Qlik Expert and Result was it is not a right solution to use Rest Connector for Google Analytic. QV Source is the only solution where you can get data on which you can do reporting. I lost that thread so I can show you how it all was started.