Focus state in Default Main Dark swatch is not visible.

[Xizario]

Reproducible for buttons and breadcrumb (might be encountered in other components as well) .

Steps to reproduce:

1. Open https://www.telerik.com/kendo-react-ui/components/buttons/button/ , or the Theme Builder
2. Choose Dark Main theme.
3. Focus a button. The border is not visible. (it is visible for primary and flat buttons only)

[NikoPenev21]

https://github.com/telerik/web-components-ux/issues/471