chore(deps): update dependency com.google.protobuf:protobuf-java to v3.21.1 (#2079)

[![Mend Renovate](https://app.renovatebot.com/images/banner.svg)](https://renovatebot.com)

This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [com.google.protobuf:protobuf-java](https://developers.google.com/protocol-buffers/) ([source](https://togithub.com/protocolbuffers/protobuf)) | `3.21.0` -> `3.21.1` | [![age](https://badges.renovateapi.com/packages/maven/com.google.protobuf:protobuf-java/3.21.1/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/com.google.protobuf:protobuf-java/3.21.1/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/com.google.protobuf:protobuf-java/3.21.1/compatibility-slim/3.21.0)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/com.google.protobuf:protobuf-java/3.21.1/confidence-slim/3.21.0)](https://docs.renovatebot.com/merge-confidence/) |

---

### Release Notes

<details>
<summary>protocolbuffers/protobuf</summary>

### [`v3.21.1`](https://togithub.com/protocolbuffers/protobuf/compare/v3.21.0...v3.21.1)

[Compare Source](https://togithub.com/protocolbuffers/protobuf/compare/v3.21.0...v3.21.1)

</details>

---

### Configuration

📅 **Schedule**: Branch creation - At any time (no schedule defined), Automerge - At any time (no schedule defined).

🚦 **Automerge**: Disabled by config. Please merge this manually once you are satisfied.

♻ **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

🔕 **Ignore**: Close this PR and you won't be reminded about this update again.

---

 - [ ] <!-- rebase-check -->If you want to rebase/retry this PR, click this checkbox.

---

This PR has been generated by [Mend Renovate](https://www.mend.io/free-developer-tools/renovate/). View repository job log [here](https://app.renovatebot.com/dashboard#github/googleapis/google-api-java-client).

Author: renovate-bot

pom.xml

@@ -499,7 +499,7 @@
     <project.oauth.version>1.34.0</project.oauth.version>
     <project.jsr305.version>3.0.2</project.jsr305.version>
     <project.gson.version>2.8.6</project.gson.version>
-    <project.protobuf-java.version>3.21.0</project.protobuf-java.version>
+    <project.protobuf-java.version>3.21.1</project.protobuf-java.version>
     <project.guava.version>31.1-jre</project.guava.version>
     <project.appengine.version>2.0.5</project.appengine.version>
     <project.xpp3.version>1.1.4c</project.xpp3.version>