updateWith() method - state machine checks

Click on each button in sequence from top to bottom without refreshing the page. Each button will bring up the Payment Request UI window.

When the payment sheet is shown, select a different shipping address once. Then pay.

1. When updateWith() is called, if request.[[state]] is not "interactive", then throw an " InvalidStateError" DOMException.
2. When updateWith() is called, If request.[[updating]] is true, then throw an "InvalidStateError" DOMException.
3. Done!