Add a builder for payment configurations?

[plusmobileapps]

I see the approach of providing a configuration to the Google Pay example is done through a JSON file which is similar to my initial crack at this a couple of years ago. I know the Google Pay API itself is JSON based and this could be provided as an option for a type of configuration, although something less error prone for a developer to construct might be a builder class for each kind of payment configuration?

Was thinking something similar to this other flutter_pay package potentially.

//Also you can state allowed payment card networks:
bool isAvailable = await flutterPay.canMakePaymentsWithActiveCard(
	allowedPaymentNetworks: [
		PaymentNetwork.visa, 
		PaymentNetwork.masterCard,
	],
);