Allow setting the update strategy for the API server in the HELM chart

[tralios]

Currently, the Dependency-Track Helm chart always uses the default strategy "RollingRelease" to update the StatefulSet or Deployment of the API server. We would like to be able to set this strategy ourselves.

Current behavior
No value is set, so kubernetes defaults are applied, depending on the deploymentType set in the values.yaml:
https://kubernetes.io/docs/concepts/workloads/controllers/statefulset/#update-strategies

  updateStrategy:
    rollingUpdate:
      partition: 0
    type: RollingUpdate

https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#strategy

  strategy:
    rollingUpdate:
      maxSurge: 25%
      maxUnavailable: 25%
    type: RollingUpdate

Desired behavior
We would like to add a parameter to the values.yaml that allows setting this to a different value. For example when using a Deployment:

  strategy:
    type: Recreate

If this feature is of interest, we can create a PR with the needed changes.