Products API response not getting mapped completely in Java uber-rides SDK

[saurabhexpedia]

https://developer.uber.com/docs/riders/references/api/v1.2/products-get
GET v1.2/products API exposes multiple attributes. Out of this few attributes like
'cost_per_minute', 'distance_unit', 'minimum', 'price_details' are not getting mapped in JAVA SDK.

The model class Product does not contain these attributes and needs to be enhanced.

Please update the models.

Let me know if you want me to submit a PR.

[saurabhexpedia]

I am ready with my code changes. Please provide me the required permissions so that I can submit the pull-request.