Updating default values and changing event data.

Updating the event in response to comments in the ticket ECOM-546.  Changing the values emitted by the google analytics event.

@wedaly @rlucioni 
This is the line introduces a pylint violation which is causing the build to fail. Specifically,
```
E1101: (no-member), OrderItem.analytics_data: Instance of 'OrderItem' has no 'id' member
```