R1:099c90e7ec9d

Remove "First Message" from New Conpherence Room workflow

Summary: Removes this feature, makes creating a room simpler and less confusing.

Test Plan: Create a room on Conpherence.

Reviewers: epriestley

Reviewed By: epriestley

Subscribers: Korvin

Differential Revision: https://secure.phabricator.com/D17661