I’ve been seeing log messages with (invalid) when the setHeaderRoute step completes, so I added a Routing CanaryStepString field to improve log readability.

• AS-IS:

Rollout step n/n completed (invalid)

• TO-BE:

Rollout step n/n completed (setHeaderRoute: foo)

Checklist:

• Either (a) I've created an enhancement proposal and discussed it with the community, (b) this is a bug fix, or (c) this is a chore.
• The title of the PR is (a) conventional with a list of types and scopes found here, (b) states what changed, and (c) suffixes the related issues number. E.g. "fix(controller): Updates such and such. Fixes #1234".
• I've signed my commits with DCO
• I have written unit and/or e2e tests for my change. PRs without these are unlikely to be merged.
• My builds are green. Try syncing with master if they are not.
• My organization is added to USERS.md.