R1:b3d07ba0a93c

Fix mobile search background color

Summary: Currently, clicking search on mobile, the background gradient is bleeding.

Test Plan: Click search icon on mobile, see black and not a pony color.

Reviewers: btrahan, epriestley

Reviewed By: epriestley

Subscribers: epriestley, Korvin

Differential Revision: https://secure.phabricator.com/D8878