Material-components-android: [Feature Request] Add Neutral Button to MaterialDatePicker

[DvTonder]

Use case: There are times when one wants to clear a selected date (i.e. I have a task with a due date, I want to use the MaterialDatePicker to display the current date, pick a new date OR clear the selected date.

The first two are currently supported, the 3rd requires either the ability to extend the class and override the onCreateView (not possible because the class is final) or adding support for a Neutral button.

[melaniegoetz]

Thanks for this feature request! This is currently awaiting design feedback

[carlfindahl]

Any updates on this?

[DvTonder]

Sample implementation. I did this by copying the full class into my codebase and adding neutral button support.