Summary: Depends on D20663. Ref T13343. Currently, if an Auth message hasn't been customized yet, clicking the message type takes you straight to an edit screen to create a message. If an auth message has already been customized, you go to a detail screen instead. Since there's no detail screen on the "create for the first time" flow, we don't have anywhere to put a more detailed description or a preview of a default value. Add a view screen that works if a message is "empty" so we can add this stuff. (The only reason we don't already have this is that it took a little work to build; this also generally improves the consistency and predictability of this interface.) Test Plan: {F6607665} Reviewers: amckinley Reviewed By: amckinley Maniphest Tasks: T13343 Differential Revision: https://secure.phabricator.com/D20664