Update sample app to include Afterpay V2 example

[tir38]

We need to make a network request to the mock/local server. There were any number of ways to do this but I chose retofit/moshi because why not.

The rest of the flow in the sample activity should be pretty straight forward.

[BrianGardnerAtl]

Looks good to me. Is there a reason to keep the commented out dependency in the gradle file?

[tir38]

Looks good to me. Is there a reason to keep the commented out dependency in the gradle file?

yeah it's so we/and other devs can easily switch back between what's in this repo versus what version we've pushed to maven. Its sort of a way to check that what ended up on maven is functional.