Expose UDP port in UDP ingress example

[chotiwat]

The port protocol in the nginx UDP loadbalancing example is not specified so it defaults to TCP.

[k8s-ci-robot]

Thanks for your pull request. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please follow instructions at https://github.com/kubernetes/kubernetes/wiki/CLA-FAQ to sign the CLA.

It may take a couple minutes for the CLA signature to be fully registered; after that, please reply here with a new comment and we'll verify. Thanks.

---

• If you've already signed a CLA, it's possible we don't have your GitHub username or you're using a different email address. Check your existing CLA data and verify that your email is set on your git commits.
• If you signed the CLA as a corporation, please sign in with your organization's credentials at https://identity.linuxfoundation.org/projects/cncf to be authorized.
• If you have done the above and are still having issues with the CLA being reported as unsigned, please email the CNCF helpdesk: helpdesk@rt.linuxfoundation.org

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.

[k8s-reviewable]

This change is 

[chotiwat]

Signed the CLA.

[coveralls]

Coverage remained the same at 43.578% when pulling da01583 on chotiwat:patch-1 into 923f4d4 on kubernetes:master.

[coveralls]

Coverage remained the same at 43.578% when pulling da01583 on chotiwat:patch-1 into 923f4d4 on kubernetes:master.

[chotiwat]

My bad, that was just a registration. It's signed now.

[aledbf]

/lgtm

[aledbf]

@chotiwat thanks!