ACR bug fix: Update 'packageName' metadata check to 'org.opencontainers.image.title'

[alerickson]

PR Summary

'packageName' no longer exists as a manifest property. Small update to check for the new property name 'org.opencontainers.image.title'

Also removing extraneous '.

PR Context

PR Checklist

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• [ ] Summarized changes
• [ ] Make sure all .h, .cpp, .cs, .ps1 and .psm1 files have the correct copyright header
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