feat: add proguard/R8 support

[hurali97]

Summary

This adds the consumer-rules to the packages and exposes 2 options, minifyEnabled and extraProguardRules for brownfield.android.expo.

Test plan

• Verified locally on both Expo and RN App
• CI passes

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[artus9033]

LGTM, just one comment left

[artus9033]

Shouldn't we add this to ExpoApp55 too?

[hurali97]

It's only required if we use minification enabled and I guess for showcase perspective, doing in one app is fine?

[yassinetou9]

@hurali97 @artus9033 The extraProguardRules array is joined directly into the generated proguard-rules.pro file with no validation. Invalid ProGuard syntax will only be caught at Gradle build time, making it hard to diagnose.

Consider adding a simple validation check in resolveBrownfieldPluginConfig or when rendering the template. For example:

const extraProguardRules = (effectiveProps.android?.extraProguardRules ?? [])
  .filter(rule => rule.trim().length > 0);

And document in the schema that each rule must be a non-empty string. This catches silent failures early.

[yassinetou9]

@hurali97 @artus9033 The -dontwarn rules for Material and Java invoke classes appear in:

• packages/react-native-brownfield/src/expo-config-plugin/template/android/proguard-rules.pro
• apps/RNApp/android/BrownfieldLib/proguard-rules.pro

These rules are identical and could be centralized in the consumer-rules.pro of the main package so they're automatically included wherever the package is used, eliminating duplication.

-dontwarn com.google.android.material.R$attr
-dontwarn com.google.android.material.R$dimen
-dontwarn com.google.android.material.R$id
-dontwarn com.google.android.material.R$style
-dontwarn java.lang.invoke.StringConcatFactory

This reduces maintenance burden if these rules ever need to change.