Change placeholder value
Change placeholder value

Change SERVICE_VERSION to SERVICE_CONFIG_ID to be consistent with the Getting Started with Endpoints on Kubernetes Engine tutorial and the deployment.yaml file in the java-docs-samples, python-docs-samples, and golang samples.
GoogleCloudPlatform/ruby-docs-samples,GoogleCloudPlatform/ruby-docs-samples,GoogleCloudPlatform/ruby-docs-samples,GoogleCloudPlatform/ruby-docs-samples