Add some missing strings for custom policies

Summary: Ref T603. Fix/provide some rendering stuff related to custom policies.

Test Plan: After setting stuff to custom policies (made easier by future diffs), looked at the various places strings appear in the UI and saw more sensible ones.

Reviewers: btrahan

Reviewed By: btrahan

CC: aran

Maniphest Tasks: T603

Differential Revision: https://secure.phabricator.com/D7297