Zones column not populated for GCE clusters

[rramkumar1]

/kind bug

1. What kops version are you running? The command kops version, will display
this information.

1.34

2. What Kubernetes version are you running? kubectl version will print the
version if a cluster is running or provide the Kubernetes version specified as
a kops flag.

N/A

3. What cloud provider are you using?

gce

4. What commands did you run? What is the simplest way to reproduce this issue?

rramkumar@rramkumar:~$ kops get cluster --state=gs://rramkumar-kops-test
NAME                    CLOUD   ZONES
alias.k8s.local         gce
repro.example.com       gce
simple.k8s.local        gce

5. What happened after the commands executed?

See above

6. What did you expect to happen?

Zones column should be populated

**7. Please provide your cluster manifest. Execute

N/A

8. Please run the commands with most verbose logging by adding the -v 10 flag.
Paste the logs into this report, or in a gist and provide the gist link here.

9. Anything else do we need to know?

[rramkumar1]

GCE subnets are regional which is why we can't leverage the spec.subnet.zone field.

[rramkumar1]

Perhaps its worth it to store the zones in a separate field here for the sole purpose of outputting it during kops get?