How to access variant.outputFileName in Kotlin

A little simplified version of @david.mihola answer:

android {

    /**
    * Notes Impl: Use DomainObjectCollection#all
    */
    applicationVariants.all {
        val variant = this
        variant.outputs
            .map { it as com.android.build.gradle.internal.api.BaseVariantOutputImpl }
            .forEach { output ->
                val outputFileName = "YourAppName - ${variant.baseName} - ${variant.versionName} ${variant.versionCode}.apk"
                println("OutputFileName: $outputFileName")
                output.outputFileName = outputFileName
            }
    }

}