Restore green color on mobile calendar month view when a day contains events you are invited to

Summary: Ref T11816. This got dropped somewhere along the way, so the mobile month view no longer showed a green-colored hint if a day has events you're invited to.

Test Plan: Viewed Calendar month view on mobile, saw green circles for days with invited events.

Reviewers: chad

Reviewed By: chad

Maniphest Tasks: T11816

Differential Revision: https://secure.phabricator.com/D16852