Java reflection not working on Android 5.1.1 version

I am trying to fix drop down list height of spinner using following method.But it doesn't seems to be working on android 5.1.1 and below.

 private void setSpinnerDropDownHeight() {
    try {
        Field popup = Spinner.class.getDeclaredField("mPopup");
        popup.setAccessible(true);

        // Get private mPopup member variable and try cast to ListPopupWindow
        android.widget.ListPopupWindow popupWindow = (android.widget.ListPopupWindow) popup.get(logWorkBinding.depotSpinner);

        // Set popupWindow height to 500px
        popupWindow.setHeight(700);
    } catch (NoClassDefFoundError | ClassCastException | NoSuchFieldException | IllegalAccessException e) {
        Log.e("Exception", "setSpinnerDropDownHeight: " + e.getLocalizedMessage());
    }
}

Thanks