Add toggle for PodDisruptionBudget in chart

[AndrewSirenko]

Is this a bug fix or adding new feature?

/feature

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

Fixes #1934

The EBS CSI Controller Pod's PodDisruptionBudget ensures that 1 controller Pod is always running, even when many nodes are being drained at once. This ensures that PersistentVolumes are always able to be Attached/Detached Created/Deleted, and that stateful pods are not delayed by missing PVs.

Some customers have requested ability to disable this PodDisruptionBudget in order to prioritize node draining / Karpenter consolidation over the availability of the EBS CSI Driver. While we don't recommend this, this PR exposes the parameter for those who use EBS only with non-critical applications.

**What testing is

See the following rendered helm templates with and without --set controller.podDisruptionBudget=false, along with the diff

change.txt default.txt diff.txt done?**

Diff:

2,22d1
< # Source: aws-ebs-csi-driver/templates/poddisruptionbudget-controller.yaml
< apiVersion: policy/v1
< kind: PodDisruptionBudget
< metadata:
<   name: ebs-csi-controller
<   namespace: default
<   labels:
<     app.kubernetes.io/name: aws-ebs-csi-driver
<     app.kubernetes.io/instance: release-name
<     helm.sh/chart: aws-ebs-csi-driver-2.33.0
<     app.kubernetes.io/version: "1.33.0"
<     app.kubernetes.io/component: csi-driver
<     app.kubernetes.io/managed-by: Helm
< spec:
<   selector:
<     matchLabels:
<       app: ebs-csi-controller
<       app.kubernetes.io/name: aws-ebs-csi-driver
<       app.kubernetes.io/instance: release-name
<   maxUnavailable: 1
< ---

Proof in deployed cluster:

❯ helm upgrade \
  --install aws-ebs-csi-driver \
  ... 
  --set controller.podDisruptionBudget=false

❯ kubectl get pdb -A
NAMESPACE     NAME                           MIN AVAILABLE   MAX UNAVAILABLE   ALLOWED DISRUPTIONS   AGE
kube-system   aws-node-termination-handler   N/A             1                 1                     105m
kube-system   cilium-operator                N/A             1                 1                     105m
kube-system   kube-dns                       N/A             50%               1                     105m

[github-actions[bot]]

Code Coverage Diff

This PR does not change the code coverage

[ElijahQuinones]

/retest

[torredil]

/lgtm

[AndrewSirenko]

/hold

Wait for #2106 to merge first

[torredil]

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: torredil

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[AndrewSirenko]

/unhold