Bump gson from 2.7 to 2.8.9

Bumps [gson](https://github.com/google/gson) from 2.7 to 2.8.9.
- [Release notes](https://github.com/google/gson/releases)
- [Changelog](https://github.com/google/gson/blob/master/CHANGELOG.md)
- [Commits](google/gson@gson-parent-2.7...gson-parent-2.8.9)

---
updated-dependencies:
- dependency-name: com.google.code.gson:gson
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>

pom.xml

@@ -49,7 +49,7 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <avro.version>1.9.2</avro.version>
-        <gson.version>2.7</gson.version>
+        <gson.version>2.8.9</gson.version>
         <slf4j.version>1.7.32</slf4j.version>
         <log4j.version>2.17.1</log4j.version>
         <maven.compiler.source>1.8</maven.compiler.source>