R1:8f48968c6eb9

Fix missing button to expand project action list on mobile.

Test Plan: Go to a project page, make browser window narrow, click to expand action list.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley

CC: Korvin, epriestley, aran

Differential Revision: https://secure.phabricator.com/D7666