R1:4068aaef61a0

Toggle revision "shouldBroadcast" correctly when "--draft" is used with prototypes off

Summary:
See PHI573. Ref T13120. Drafts were recently changed so that "draft" and "broadcast" are separate flags, and you can have non-broadcasting revisions in states other than "draft" if builds fail on a draft or you abandon a draft.

However, when draft mode is entered with `arc diff --draft` and you have prototypes off, this flag wasn't being set correctly.

Test Plan: Disabled prototypes, created a revision with…