Default button causing `plain` on TextInput, Select, etc. doesn't allow keyboard visual indication of active suggestion/option

Expected Behavior

When default button is defined in theme and user uses keyboard to move through textinput suggestions, select options, etc., the hover styling should still be applied.

Actual Behavior

No styling is being applied because the button is marked as plain, so there’s no indication of which suggestion or select option is active. This only is an issue when default button is defined on theme.

These changes are rooted in this PR: https://github.com/grommet/grommet/pull/4131 However, this PR is solving some issues we were facing such as unwanted padding, bold font, etc. but it is the reason that the keyboard styling is not visible.

URL, screen shot, or Codepen exhibiting the issue

Current implementation with grommet-theme-hpe-next. I am using keyboard to navigate but can’t get the visual indication of which option i’m on:

With plain removed (however, this causes unwanted implications of extra padding, bold font, etc.), but the necessary visual indication of keyboard navigation returns:

Steps to Reproduce

See the above gifs

Your Environment

• Grommet version: stable
• Browser Name and version: chrome
• Operating System and version (desktop or mobile): macos

[ericsoderberghp]

agreed

[ShimiSun]

Fixed on #4163