Backport of NET-10548 Adds image pull secrets to the gateway cleanup and gateway resources job service account into release/1.5.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #4210 to be assessed for backporting due to the inclusion of the label backport/1.5.x.

The below text is copied from the body of the original PR.

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This fixes #3862. When installing consul-k8s with a private image registry, the 'gateway-resources' and 'gateway-cleanup jobs could not pull the images as thier service accounts did not include the imagePull secrets

How I've tested this PR

• Added bats test
• Manually tested with the following values and a private registry set up
  Do a helm install with the local chart from this branch. If the jobs didn't have the required pull secrets, they would never spin up.
  Also do a helm uninstall to see the cleanup-job run.

global:
  name: consul
  imageK8S: my-private-registry/consul-k8s-control-plane:latest
  imagePullSecrets:
  - name: consul-pull-secret
    namespace: consul
# This is useful to make sure it is always pulling the image, and not just getting it from another container on the cluster
  imagePullPolicy: "Always" 

How I expect reviewers to test this PR

Test on your own cluster with a private registry using the above values.

Checklist

• Tests added
• CHANGELOG entry added

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Overview of commits

• 18f135e - ffa2fd6