show/hide android status bar using kotlin

fullscreen.kt

override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_splash_screen)
        //make Activity fullscreen /*hide Status bar*/
        window.setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,WindowManager.LayoutParams.FLAG_FULLSCREEN)

        val button=findViewById<Button>(R.id.button)
        button.setOnClickListener {
            //Back Activity to normal screen /*Show Status bar*/
            window.clearFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN)
        }
    }