[BUG] Activity.onBackPressed() implementation should be replaced with OnBackPressedCallback

[fbarthelery]

Summary

Following on #5844, if an application that uses stripe-android library has opt-in to predictive back gesture, Activity.onBackPressed() callback will not be called when user press the back button.
This will cause various bugs as some activities expect onBackPressed() to be called.
onBackPressed() implementation should be replaced with OnBackPressedCallback

Code to reproduce

Opt in to predictive back gesture, launch one of the affected activity. Press back button. onBackPressed() is not called

Android version

Android 13 api 33

SDK classes

After a quick search, I listed some implementation of onBackPressed() in the codebase:

• FinancialConnectionsSheetActivity
• BaseSheetActivity
• PaymentFlowActivity
• PaymentAuthWebViewActivity
• PaymentMethodsActivity
• ScanActivity
• CardScanActivity

[tillh-stripe]

Hi there 👋 Thanks for bringing this to our attention. We’ll improve support for the predictive back gesture behavior and include this in our next release.

[tillh-stripe]

Just released as part of version 20.18.0.