dynamic_version.gradle

def versionPropsFile = file('version.properties')

    if (versionPropsFile.canRead()) {
        Properties versionProps = new Properties()

        versionProps.load(new FileInputStream(versionPropsFile))

        def code = versionProps['VERSION_CODE'].toInteger() + 1
        def name = versionProps['VERSION_NAME']

        versionProps['VERSION_CODE'] = code.toString()
        versionProps.store(versionPropsFile.newWriter(), null)

        defaultConfig {
            applicationId "com.app.id"
            minSdkVersion 16
            targetSdkVersion 27
            versionCode code
            versionName name + " - " + code
            testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
            multiDexEnabled true
            vectorDrawables.useSupportLibrary = true
        }
    } else {
        throw new GradleException("Could not read version.properties!")
    }