Update gcpserving.py

[cpcgoogle]

pod_template_spec is a required field in deploy() but it looks like the parameter is never used. Maybe default to making it an empty string so users are not confused at what should be passed in to run the deployment.

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[k8s-ci-robot]

Hi @cpcgoogle. Thanks for your PR.

I'm waiting for a kubeflow member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[jinchihe]

/ok-to-test

[k8s-ci-robot]

@cpcgoogle: The following test failed, say /retest to rerun all failed tests:

Test name	Commit	Details	Rerun command
kubeflow-fairing-presubmit	3d38d1e	link	/test kubeflow-fairing-presubmit

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

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