call onrestart/onresume when click on back button
Intent intent = new Intent(Start.this, CitySelect.class);
View view = TestActivity.group.getLocalActivityManager().startActivity("cityselect", intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)).getDecorView();
TestActivity.group.replaceView(view);

public void replaceView(View v)
{
    history.add(v);
    setContentView(v);
}

@Override
public void onBackPressed()
{
    TestActivity.group.back();
}

public void back()
{
    if (history.size() > 0)
    {
        history.remove(history.size() - 1);

        if (history.size() > 0)
        {
            View v = history.get(history.size() - 1);
            setContentView(v);
        }

        else
        {
            finish();
        }
    }

    else
    {
        finish();
    }
}

Intent intent = new Intent(Start.this, CitySelect.class);
View view =     TestActivity.group.getLocalActivityManager().startActivity("cityselect", intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)).getDecorView();
TestActivity.group.replaceView(view,"cityselect");

public void replaceView(View v, String activityId)
{
    history.add(activityId);
    setContentView(v);
}

public void back()
{
if (history.size() > 0)
{
    history.remove(history.size() - 1);

    if (history.size() > 0)
    {
        //View v = history.get(history.size() - 1);
        //setContentView(v);

       LocalActivityManager manager = getLocalActivityManager();
       String lastId = mIdList.get(history.size()-1);
       Intent lastIntent = manager.getActivity(lastId).getIntent();
       Window newWindow = manager.startActivity(lastId, lastIntent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP));
       setContentView(newWindow.getDecorView());

    }

    else
    {
        finish();
    }
}

else
{
    finish();
}