function _updatePicker() {
        var filter = getActiveFilter();
        if (filter && filter.patterns.length) {
            var label = filter.name || _getCondensedForm(filter.patterns);
            _picker.setButtonLabel(StringUtils.format(Strings.EXCLUDE_FILE_FILTER, label));
        } else {
            _picker.setButtonLabel(Strings.NO_FILE_FILTER);
        }
    }
Update the picker button label with the name/patterns of the selected filter or
No Files Excluded if no filter is selected.