builtin/k8s: Ensure pod.container.static_environment is applied

[jgwhite]

Why the change?

I noticed that the following configuration did not apply the env vars to the app container as expected.

deployment {
  use "kubernetes" {
    pod {
      container {
        static_environment = {
          "MY_COOL_ENV_VAR" = "MY_COOL_VALUE"
        }
      }
      # ...

How do I test this?

1. git checkout k8s/container-static-env
2. make bin
3. Configure a deployment with pod.container.static_environment as above
4. Deploy
5. Verify the defined env vars were applied to the app container correctly
6. Try hoisting the static_environment config:

   deployment {
     use "kubernetes" {
       static_environment = {
         # ...

7. Deploy again
8. Verify the env vars are still applied correctly

[briancain]

🙏🏻