Desliga celular em 10 segundos e necessário root

Button button = (Button) findViewById(R.id.button1);
final EditText editText = (EditText) findViewById(R.id.editText1);

button.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View view) {
        final Timer timer = new Timer();
        timer.scheduleAtFixedRate(new TimerTask() {
            @Override
            public void run() {
                Calendar c = Calendar.getInstance();
                int seconds = c.get(Calendar.SECOND);
                final String time = String.valueOf(seconds);
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        editText.setText(time);
                        if (time.equals("10")) {
                            try {
                                Runtime.getRuntime().exec("su -c reboot -p");
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                            timer.cancel();
                        }
                    }
                });
            }
        }, 0, 1000);
    }
});