Revert "[Expressive design] Update dropdown item color"

Revert submission 33670475-dropdown_color

Reason for revert: <Potential culprit for b/419783022  verifying through ABTD before revert submission. This is part of the standard investigation process, and does not mean your CL will be reverted>

Reverted changes: /q/submissionid:33670475-dropdown_color

Bug: 419783022
Change-Id: I34b24c911faa7a4ba417bfab7ea817a3bc3bfd4c