Changing currency variable according to google analytics docs

Hi,

I'm using a store in BRL currency and tracking its sales with Google Analytics. I noticed that I was getting all revenue values in dollar, except the product price revenue.

I revisited the recommended analytics docs, and found that the `currencyCode` is actually `currency`. Here is the Google Analytics docs link: https://developers.google.com/analytics/devguides/collection/analyticsjs/ecommerce#multicurrency