Summary: Depends on D3948. First in a series of refactors to repurpose Flags for the new setup.

Test Plan: All tests pass, no changes other than a rename

Reviewers: nserrino, jamesbartlett, #engineering

Reviewed By: nserrino, #engineering

JIRA Issues: PL-1630

Differential Revision: https://phab.corp.pixielabs.ai/D3964

GitOrigin-RevId: 9492984e8863f5a44ebf8c8138843ee80ed5c7f6