Update example to apps/v1 (#6534)
Update example to apps/v1 (#6534)

## Description

I'm not certain if this is correct, but when I was following the following documentation:

https://cloud.google.com/endpoints/docs/grpc/get-started-kubernetes-engine#deploying_the_sample_api_and_esp_to_the_cluster

I was getting the following error message:

```
no matches for kind "Deployment" in version "extensions/v1beta1"
```

Which lead me to the following GitHub issue:

https://github.com/coreos/etcd-operator/issues/2126#issuecomment-561100503

So, here's the fix that made the example work for me again.
GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples,GoogleCloudPlatform/python-docs-samples