buildTypes {
    release {
        minifyEnabled false
proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
signingConfig getSigningConfig()
        applicationVariants.all { variant ->
            variant.outputs.each { output ->
                output.outputFile = new 
 
File(output.outputFile.parent,
                        output.outputFile.name.replace("app-release", "MyApkName-" + defaultConfig.versionName)
                )
            }
        }
    }
}