Correct secondary and flat button active state background color

Secondary and flat buttons have hig-teal as background color when active. It should be something else.

Reproduce the active state for secondary and flat buttons, then inspect the button styling entry points to identify where the hig-teal background is assigned. Confirm the intended replacement color with the design system before changing anything; done means both active states use the approved background color.

Written by the indexing model from the issue text.