Custom Select: Add explicit aria-label to button and export component.

packages/components/src/custom-select/index.js

@@ -84,6 +84,7 @@ export default function CustomSelect( { label, items } ) {
 			</span>
 			<Button
 				{ ...getToggleButtonProps( {
+					'aria-label': label,
 					className: 'components-custom-select__button',
 				} ) }
 			>

packages/components/src/index.js

@@ -10,6 +10,7 @@ export { default as ClipboardButton } from './clipboard-button';
 export { default as ColorIndicator } from './color-indicator';
 export { default as ColorPalette } from './color-palette';
 export { default as ColorPicker } from './color-picker';
+export { default as CustomSelect } from './custom-select';
 export { default as Dashicon } from './dashicon';
 export { DateTimePicker, DatePicker, TimePicker } from './date-time';
 export { default as Disabled } from './disabled';