What is the keycode for multitasking/appswitch for

问题:

Our app is crashing (it says "application has stopped) after we longpress the home button on samsung galaxy s3 (the longpress button is used to popup the multitasking screen/app switch dialog) we do not have this problem on our another testing device htc evo 3d so what is the keycode for this "action" ? and how can we disable this function ?

This code sadly does not work:

public boolean onKeyDown(int keyCode, KeyEvent event) {
    if(keyCode == KeyEvent.KEYCODE_APP_SWITCH) {
        System.exit(0);
            return false;
    }
    return super.onKeyDown(keyCode, event);
}