Auto-enable VAC on clusters with beta API version

[ConnorJC3]

Is this a bug fix or adding new feature?

Feature

What is this PR about? / Why do we need it?

Automatically enable VAC on clusters using the beta API version. This improves the experience for beta users and ensures they do not accidentally create a volume with a VAC bound that was not applied due to the feature gate being disabled.

Also updates the VAC documentation to reflect this, and fix a few minor issues.

What testing is done?

Templating:

$ helm template charts/aws-ebs-csi-driver | grep VolumeAttributesClass
<blank output>

$ helm template charts/aws-ebs-csi-driver --api-versions "storage.k8s.io/v1beta1/VolumeAttributesClass" | grep VolumeAttributesClass
            - --feature-gates=VolumeAttributesClass=true
            - --feature-gates=VolumeAttributesClass=true

Also tested manually on a cluster with and without VAC enabled and observed the desired effect.

[github-actions]

Code Coverage Diff

This PR does not change the code coverage

[AndrewSirenko]

Great change, thank you!

[torredil]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

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