remove pod mount path when NodeUnpublishVolume is called

[carlory]

Description

FYI: https://github.com/kubernetes/kubernetes/pull/121978

Checklist

• [ ] tested locally
• [ ] updated any relevant dependencies
• [ ] updated any relevant documentation or examples

Testing Done

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Issue

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Fixes #

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This change is 

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[arunmk]

@carlory I think there is some rebase / merge-conflict-resolution needed. Can you please do that and we can merge it.