
added functionality to onPressed method to communicate button press action to screen readers. Before: https://screencast.googleplex.com/cast/NjI2NzEyMzY3OTYyNTIxNnw1NjgyNGE3MC0wNQ After: https://screencast.googleplex.com/cast/NjUyODAxNzc0MzQ3ODc4NHwxNjBhZDZjNi1hOA fixes b/347102786