Gradle code to make APK files have a sensible format

artifacts.gradle.txt

// Makes the APKs we build be called AppName-release-buildVariant-1.2.3_4.apk
//
// To use, add this file to the root of your project (next to gradle.properties) make sure the name is artifacts.gradle.
// Then edit gradle.properties to include:  `applicationName=MyAppName`
// Then edit module build.gradle, add at the end `apply from: "../artifacts.gradle"`
//
// Adapted slightly from https://www.jayway.com/2015/03/13/producing-better-named-android-apks-with-gradle/
android.applicationVariants.all { variant ->
    def appName
    //Check if an applicationName property is supplied; if not use the name of the parent project.
    if (project.hasProperty("applicationName")) {
        appName = applicationName
    } else {
        appName = parent.name
    }

    variant.outputs.each { output ->
        def newApkName
        //If there's no ZipAlign task it means that our artifact will be unaligned and we need to mark it as such.
        if (output.zipAlign) {
            newApkName = "${appName}-${output.baseName}-${variant.versionName}_${variant.versionCode}.apk"
        } else {
            newApkName = "${appName}-${output.baseName}-${variant.versionName}_${variant.versionCode}-unaligned.apk"
        }
        output.outputFile = new File(output.outputFile.parent, newApkName)
    }
}