private void updateHoursMinutesSeconds() {
        hoursView.setText(input.getHoursString());
        minutesView.setText(input.getMinutesString());
        secondsView.setText(input.getSecondsString());
        fireDurationChangeListener();
    }
Sets the padding to be used for the number pad buttons.

@param padding padding in pixels
android/third_party/time-duration-picker/src/main/java/mobi/upod/timedurationpicker/TimeDurationPicker.java