chore(deps): update dependency org.apache.maven.plugins:maven-checkstyle-plugin to v3.1.2 (googleapis#824)

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This PR contains the following updates:

| Package | Change | Age | Adoption | Passing | Confidence |
|---|---|---|---|---|---|
| [org.apache.maven.plugins:maven-checkstyle-plugin](https://maven.apache.org/plugins/) ([source](https://github.com/apache/maven-checkstyle-plugin)) | `3.0.0` -> `3.1.2` | [![age](https://badges.renovateapi.com/packages/maven/org.apache.maven.plugins:maven-checkstyle-plugin/3.1.2/age-slim)](https://docs.renovatebot.com/merge-confidence/) | [![adoption](https://badges.renovateapi.com/packages/maven/org.apache.maven.plugins:maven-checkstyle-plugin/3.1.2/adoption-slim)](https://docs.renovatebot.com/merge-confidence/) | [![passing](https://badges.renovateapi.com/packages/maven/org.apache.maven.plugins:maven-checkstyle-plugin/3.1.2/compatibility-slim/3.0.0)](https://docs.renovatebot.com/merge-confidence/) | [![confidence](https://badges.renovateapi.com/packages/maven/org.apache.maven.plugins:maven-checkstyle-plugin/3.1.2/confidence-slim/3.0.0)](https://docs.renovatebot.com/merge-confidence/) |

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Author: renovate-bot

pom.xml

@@ -241,7 +241,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-checkstyle-plugin</artifactId>
-        <version>3.0.0</version>
+        <version>3.1.2</version>
         <executions>
           <execution>
             <id>checkstyle</id>