STOR-829: Add CSIInlineVolumeAdmission feature gate

[dobsonj]

This adds an OCP feature gate for a CSI Inline Volume Admission Plugin
behind TechPreviewNoUpgrade for 4.12.

Enhancement: openshift/enhancements#1240

/cc @openshift/storage

[openshift-ci]

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[jsafrane]

/lgtm
from storage POV

[dobsonj]

/assign @JoelSpeed

[JoelSpeed]

I don't have an issue with the code change here and I see @deads2k has approved the enhancement, but I do have a question about targeting this to 4.12. How many components need to be updated with the vendor after this and how much feature work is there still to merge? We have less than 4 days til the branch cuts and adding a new feature at this point seems like it's likely not to land in time

Is the code ready to go?

[jsafrane]

I think branching day was postponed by 3 weeks.

How many components need to be updated with the vendor after this

IMO just kube-apiserver-operator, the feature is implemented as an admission plugin in the API server (like SCC).

how much feature work is there still to merge

A lot :-). It's a tough deadline, still, I think we can do it in the ~3-4 remaining weeks.

[JoelSpeed]

Feature complete target is 7th October 2022 according to the release dates spreadsheet, is this project following the no-ff procedures?

[jsafrane]

Yes, we're no-ff.

[JoelSpeed]

Given no-ff this means you have just shy of 4 weeks, with that I think it's ok to merge this at this point
/approve

[openshift-ci]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dobsonj, JoelSpeed, jsafrane

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[dobsonj]

Since this is just adding a feature gate, there's nothing to document or test yet. Need this merged so I can check the feature gate from the admission plugin in the real PR.
/label px-approved
/label docs-approved
/label qe-approved

[openshift-ci]

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