Bump org.apache.maven.plugins:maven-checkstyle-plugin (#1684)

Author: dependabot[bot]

pom.xml

@@ -291,7 +291,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-checkstyle-plugin</artifactId>
-        <version>3.5.0</version>
+        <version>3.6.0</version>
         <configuration>
           <configLocation>google_checks.xml</configLocation>
           <failOnViolation>true</failOnViolation>