fix: volcano podgroup should has a non-empty queue name

[lowang-bh]

What this PR does / why we need it:

Which issue(s) this PR fixes (optional, in Fixes #<issue number>, #<issue number>, ... format, will close the issue(s) when PR gets merged):
Fixes #1967

Checklist:

• Docs included if any changes are user facing

[coveralls]

Pull Request Test Coverage Report for Build 7444891160

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.1%) to 42.931%

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Totals
Change from base Build 7423814404:	0.1%
Covered Lines:	3759
Relevant Lines:	8756

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💛 - Coveralls

[johnugeorge]

Thanks @lowang-bh
/lgtm
/approve

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: johnugeorge, lowang-bh

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