Use a less-misleading example for Conduit custom constraints

Summary:
See PHI2032. The Conduit UI shows some "Example Custom Constraints" that are intended to be generic, but use of "statuses" is misleading since many objects have a status and most of them don't support these specific values.

Make it more clear that these are generic values.

Test Plan: Read new text.

Differential Revision: https://secure.phabricator.com/D21637