Ensure kustomize does not get updated until after image is available in all registries.

[wongma7]

/kind bug

What happened? For 1.1.3, (and to lesser extent all other bugfix releases), the kustomize template was updated before the image was actually in GCR.

Update the release process so that the kustomize template PR gets merged AFTER the image builds succeed https://github.com/kubernetes-sigs/aws-ebs-csi-driver/blob/master/docs/RELEASE.md.

The same problem used to exist for helm and we already fixed that by changing the process so that maintainers merge the master branch change and trigger a helm chart release AFTER the image build succeed, basically we need to also do the same for our kustomize users.

/assign

CC #993

What you expected to happen?

How to reproduce it (as minimally and precisely as possible)?

Anything else we need to know?:

Environment

• Kubernetes version (use kubectl version):
• Driver version:

[wongma7]

BTW, I think it's an oversight because for a minor version 1.y.0 release, of course you are creating the release-1.y branch for the first time, so there is no harm in merging the kustomize template before changing the master branch kustomize command to point to the release-1.y branch.

But for a patch 1.y.x release, the master branch kustomize command already points to the release-1.y branch so we really ahve to be careful not to modify it.