Update job.go

[minzhuogoogle]

Add metadata in order to extract metadata in podinfo.json

[google-oss-prow[bot]]

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[google-oss-prow[bot]]

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[michelle192837]

Hi! Just checking, but what's the reason for this addition? (iiuc I think podinfo.json isn't always expected to be uploaded, but the relevant metadata should be present in finished.json if needed)