There was a timing issue with staging flash, due to the automated staging Pipeline grabbing the files to package the crx before everything was copied over.

One potential solution would be to write the manifest.json file to each platform directory last, when we're copying, so that there is a clear signal when the copying is complete.

Meaning to change the order of archive to gs to:

1) for each platforms, upload everything but manifest.json (retaining normal directory structure)
2) for each platform, upload manifest.json