feat: init deploy-gke Container Action

[JeromeJu]

This commit inits the deploy-gke container action. It utlizes the gke-deploy CLI image to deploy an existing image to a GKE cluster.

The integration test, documentation and CI setup are included within this initial commit.

[sethvargo]

@JeromeJu looks like integration tests are failing. I can force-merge this if you're still working on CI.

[JeromeJu]

@JeromeJu looks like integration tests are failing. I can force-merge this if you're still working on CI.

Thanks for the review @sethvargo and yes I am working on the CI - taking a bit time to learn the tf syntax conventions given it's my first time going through it. I will try to put up the CI PR ASAP.

[sethvargo]

Thanks - you should have access to the test-infra repo. Do you need me to grant GCP IAM permissions so you can create resources in the GCP projects?

[JeromeJu]

Thanks - you should have access to the test-infra repo. Do you need me to grant GCP IAM permissions so you can create resources in the GCP projects?

Thanks @sethvargo - yes that would be much appreciated.
I've added google-github-actions/test-infra#65 for the required inputs for the CI workflow. I assume to make this change effective, I would need to set those values up with the IAM account via terraform?

(sorry to get back to this late - I had some issue getting notification within this org I believe earlier but I think it is fixed now; tested with a new PR)