helm: Expose volumes and volumeMounts for the ebs-csi-controller deployment

[cnmcavoy]

Is this a bug fix or adding new feature?
Feature.

What is this PR about? / Why do we need it?
Allows users who wish to integrate the controller with IRSA authentication manually (i.e not using the https://github.com/aws/amazon-eks-pod-identity-webhook) to configure the controller with the correct mounts for authentication. For example:

    volumes:
    - name: aws-token
      projected:
        sources:
        - serviceAccountToken:
            audience: "sts.amazonaws.com"
            expirationSeconds: 86400
            path: token
    volumeMounts:
    - mountPath: "/var/run/secrets/eks.amazonaws.com/serviceaccount/"
      name: aws-token

What testing is done?
Helm template verification.

[k8s-ci-robot]

Hi @cnmcavoy. Thanks for your PR.

I'm waiting for a kubernetes-sigs member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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[ConnorJC3]

/ok-to-test

[ConnorJC3]

/lgtm

[torredil]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: gtxu

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[gtxu]

/lgtm Thanks for the contribution @cnmcavoy !