test-proguard.custom-from-lib-build.gradle

android {
    buildTypes {
        release {
            minifyEnabled true
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
            
            // Also consider the library's custom ProGuard rules
            proguardFiles "${project(':thelibrary').projectDir}/proguard-rules-app.pro"
        }
    }
    // ...
}