Fix compiling against system protobuf

[sclarkson]

When trying to compile with the bazel configuration build --action_env TF_SYSTEM_LIBS="com_google_protobuf", the following errors occur.

ERROR: /home/sclarkson/tensorflow-master/tensorflow/core/data/service/BUILD:31:17: no such target '@com_google_protobuf//:any_proto': target 'any_proto' not declared in package '' defined by /home/sclarkson/.cache/bazel/_bazel_sclarkson/fffe72c6b1157d70fb0a456ab7b675c2/external/com_google_protobuf/BUILD.bazel and referenced by '//tensorflow/core/data/service:dispatcher_proto'

This PR adds the missing protobuf library definitions to successfully compile against the system protobuf.

[googlebot]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

📝 Please visit https://cla.developers.google.com/ to sign.

Once you've signed (or fixed any issues), please reply here with @googlebot I signed it! and we'll verify it.

---

What to do if you already signed the CLA

Individual signers

• It's possible we don't have your GitHub username or you're using a different email address on your commit. Check your existing CLA data and verify that your email is set on your git commits.

Corporate signers

• Your company has a Point of Contact who decides which employees are authorized to participate. Ask your POC to be added to the group of authorized contributors. If you don't know who your Point of Contact is, direct the Google project maintainer to go/cla#troubleshoot (Public version).
• The email used to register you as an authorized contributor must be the email used for the Git commit. Check your existing CLA data and verify that your email is set on your git commits.
• The email used to register you as an authorized contributor must also be attached to your GitHub account.

ℹ️ Googlers: Go here for more info.

[gbaned]

@sclarkson Thank you for your contribution. Can you please sign CLA? Thanks!

[googlebot]

CLAs look good, thanks!

ℹ️ Googlers: Go here for more info.

[sclarkson]

@gbaned Had the wrong email address on the commit. Fixed it now.

[Flamefire]

@sclarkson Thanks for that PR, ran into this too.

@gbaned @mihaimaruseac Wouldn't it somehow possible for you guys to set up a CI job that tests building with those system libs? They break with every release and require painful patching for package managers.

[mihaimaruseac]

We could attempt supporting a community based build, I think, if someone from the open source maintains it.