fix: upgrade com.google.code.gson:gson from 2.3.1 to 2.8.6

Snyk has created this PR to upgrade com.google.code.gson:gson from 2.3.1 to 2.8.6.

See this package in Maven Repository:
https://mvnrepository.com/artifact/com.google.code.gson/gson/

See this project in Snyk:
https://app.snyk.io/org/noellemurata/project/4486018f-c3a1-44e9-9b7c-96cc65a422ae?utm_source=github&utm_medium=upgrade-pr

pom.xml

@@ -56,7 +56,7 @@
         <dependency>
             <groupId>com.google.code.gson</groupId>
             <artifactId>gson</artifactId>
-            <version>2.3.1</version>
+            <version>2.8.6</version>
         </dependency>
         <dependency>
             <groupId>com.google.http-client</groupId>