issue8294: inherit k8s default volumeSnapshotClass

[hu-keyu]

Thank you for contributing to Velero!

Please add a summary of your change

Make compatible changes based on the GetVolumeSnapshotClassForStorageClass method，not break existing behaviour.

Does your change fix a particular issue?

Fixes #8294

Please indicate you've done the following:

• Accepted the DCO. Commits without the DCO will delay acceptance.
• Created a changelog file (make new-changelog) or comment /kind changelog-not-required on this PR.
• Updated the corresponding documentation in site/content/docs/main.

[hu-keyu]

review comments on PR 8719 has resovled，submit a new PR.

please reivew this PR @anshulahuja98

[hu-keyu]

please review PR #8721 , thanks

[kaovilai]

@hu-keyu this might not merge until 1.16 release is cut FYI.
Also please fix your DCO
.

[anshulahuja98]

@hu-keyu can you add this in the website docs also ?
On the page where we talk about user to put the label, we should tell them that they could also apply the annotation on VSClass.

[hu-keyu]

Which file should I add it to? @anshulahuja98

[anshulahuja98]

https://github.com/vmware-tanzu/velero/blob/main/site/content/docs/main/csi.md#implementation-choices

[anshulahuja98]

PR LGTM, CI is running currently.
We will merge this once 1.16 branch is cut. Holding onto PR Approval till then.
Thank you for your contribution @hu-keyu

[codecov]

Codecov Report

Attention: Patch coverage is 66.66667% with 3 lines in your changes missing coverage. Please review.

Project coverage is 60.44%. Comparing base (0f81772) to head (1d08b46).
Report is 96 commits behind head on main.

Files with missing lines	Patch %	Lines
pkg/util/csi/volume_snapshot.go	66.66%	2 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #8721      +/-   ##
==========================================
+ Coverage   59.48%   60.44%   +0.95%     
==========================================
  Files         371      372       +1     
  Lines       40191    41239    +1048     
==========================================
+ Hits        23909    24925    +1016     
- Misses      14789    14810      +21     
- Partials     1493     1504      +11     

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[hu-keyu]

PR LGTM, CI is running currently. We will merge this once 1.16 branch is cut. Holding onto PR Approval till then. Thank you for your contribution @hu-keyu

PR LGTM, CI is running currently. We will merge this once 1.16 branch is cut. Holding onto PR Approval till then. Thank you for your contribution @hu-keyu

[hu-keyu]

PR LGTM, CI is running currently. We will merge this once 1.16 branch is cut. Holding onto PR Approval till then. Thank you for your contribution @hu-keyu

Can this PR be merged? @anshulahuja98