[Mobile Payments] Handle cancellation from card readers #8085
Description
There is a x button to cancel the card tap from the built in reader, on Apple's payment modal. In the proof of concept, we found that this is not handled.
It's also possible to cancel from the WisePad 3 reader, which has customer-facing buttons. We don't handle that either, and should be able to fix it in the same place.
We should end the payment flow, and (for WisePad 3) show a Payment Canceled on Reader screen with a dismiss button in this situation.