Select dropdown not allowing to scroll all the options when clear selection is enabled.

Expected Behavior

Select dropdown should load all the options whether clear option is enabled or disabled.

Actual Behavior

When clear option is enable Select dropdown is not completely scrollable

URL, screen shot, or Codepen exhibiting the issue

https://codesandbox.io/s/stupefied-proskuriakova-t9r5xw

Steps to Reproduce

1. Load some dropdown options for select which has more options that enable scroll in Select.
2. Enable clear selection property for Select
3. Make a selection in the dropdown.
4. Observe you will not be able to scroll through all the options..

Your Environment

• Grommet version: > 2.21.0
• Browser Name and version: All browsers
• Operating System and version (desktop or mobile):