Adds a feature flag to #395352 (closed) to disable the new behavior by default.
This is needed for a severity2 ongoing incident gitlab-com/gl-infra/production#16042 (closed) and should be merged and deployed ASAP.
Resolves: Add automatic token reuse detection behind a FF (#418565 - closed)
This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.