Associate manifest.json with original JobStep in phased results
Associate manifest.json with original JobStep in phased results

Summary:
Fixes T59126
For real this time; previous fix was looking for manifest.json in the set of files already
guaranteed to have a non-matching name.

Test Plan: Added canary project plan in staging and prod that'll recognize it.

Reviewers: nate

Reviewed By: nate

Subscribers: changesbot, mkedia

Maniphest Tasks: T59126

Differential Revision: https://tails.corp.dropbox.com/D140529

dropbox/changes,dropbox/changes,dropbox/changes,dropbox/changes