Summary

• Add comprehensive ProGuard/R8 rules to the library's consumer rules to prevent PaymentFlowResult$Unvalidated$Companion from being stripped during minification
• This fixes the crash that occurs after completing 3D Secure authentication on Android

Problem

When using payment methods that require 3D Secure authentication (mandatory for many cards in EU/UK), the app crashes after the WebView closes with:

java.lang.NoClassDefFoundError: Failed resolution of: Lcom/stripe/android/payments/PaymentFlowResult$Unvalidated$Companion;

This happens because the library's proguard-rules.txt (distributed via consumerProguardFiles) was missing the critical -keep class com.stripe.** { *; } rule, allowing R8/ProGuard to strip essential Stripe payment flow classes.

Solution

Enhanced packages/stripe_android/android/proguard-rules.txt to include:

• -keep class com.stripe.** { *; } - Keeps all Stripe classes
• All -dontwarn rules for push provisioning and kotlinx.parcelize

These rules are now automatically applied to consuming apps via consumerProguardFiles, so users no longer need to manually add them.

Fixes #2221

Test plan

• Build a release APK with minification enabled
• Test payment with a 3D Secure card (e.g., 4000 0027 6000 3184)
• Verify no crash occurs after completing 3D Secure authentication