You can try replacing this line:
return new DatePickerDialog(this, pDateSetListener, pYear, pMonth, pDay);
By those:
DatePickerDialog dpDialog = new DatePickerDialog(this, pDateSetListener, pYear, pMonth, pDay);
DatePicker datePicker = dpDialog.getDatePicker();
Calendar calendar = Calendar.getInstance();//get the current day
datePicker.setMaxDate(calendar.getTimeInMillis());//set the current day as the max date
return dpDialog;