Port projected volume SA token from chart

[rainest]

Kong/charts#722 added support for the modern projected volume system to the chart. We should update the deployment manifests here to use the same.

Acceptance:

• The KIC deploy manifests use a projected volume for their ServiceAccount tokens.
• The projected volume configuration matches the configuration used in the chart.

[rainest]

Stuffing this in 2.9 for now since it should just be copy/paste from the chart unless we discover that there's some unexpected issue and need to rework the design.

[pmalek]

It just occurred to me that when doing this we'll be cutting out users using k8s older than 1.20.

Unless there's a mechanism in kustomize - that I'm not aware of - to make a manifest be included conditionally based on k8s version (which you can do in helm).

[seh]

Unless there's a mechanism in kustomize

There is no such mechanism, given that kustomize is not a client of the Kubernetes API.