build(deps): bump protobuf from 3.20.1 to 3.20.2 in /.kokoro (#2252)

* build(deps): bump protobuf from 3.20.1 to 3.20.2 in /.kokoro

Bumps [protobuf](https://github.com/protocolbuffers/protobuf) from 3.20.1 to 3.20.2.
- [Release notes](https://github.com/protocolbuffers/protobuf/releases)
- [Changelog](https://github.com/protocolbuffers/protobuf/blob/main/generate_changelog.py)
- [Commits](protocolbuffers/protobuf@v3.20.1...v3.20.2)

---
updated-dependencies:
- dependency-name: protobuf
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <[email protected]>

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

---------

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: dependabot[bot]