def publish = project.tasks.create("copyReleaseApkToCustomDir")
publish.description "Copies release apk to custom directory"
android.applicationVariants.all { variant ->
    if (variant.buildType.name.equals("release")) {
        variant.outputs.each { output ->
            if ( output.outputFile != null && output.outputFile.name.endsWith('.apk')) {
                def task = project.tasks.create("copyAndRename${variant.name}Apk", Copy)

                def outputFile = output.outputFile
                println "Creating " + rootProject.name + "-${versionName}.apk" + " from " + project.name + "-${variant.name}.apk"
                def fileName = outputFile.name.replace(project.name + "-${variant.name}.apk", rootProject.name +"-${versionName}.apk")
                output.outputFile = new File(outputFile.parent, fileName)

                println "Copying "+ rootProject.name + "-${versionName}.apk" + " to apk directory..."
                task.from(output.outputFile)
                task.into(buildDir.parent + "/../apk")
                println "Done"

                task.dependsOn variant.assemble
                publish.dependsOn task
            }
        }
    }
}