build.gradle

android {
    
    // other snippet
    
    flavorDimensions "default"
    productFlavors {
        prod {
            resValue "string", "build_config_package", "com.your.coolapp"
        }

        stag {
            applicationIdSuffix ".stag"
            resValue "string", "build_config_package", "com.your.coolapp"
        }

        dev {
            applicationIdSuffix ".dev"
            resValue "string", "build_config_package", "com.your.coolapp"
        }
    }
}