fix checkstyle

Author: laurit

instrumentation/armeria/armeria-grpc-1.14/javaagent/build.gradle.kts

@@ -24,6 +24,11 @@ dependencies {
   testLibrary("com.linecorp.armeria:armeria-junit5:1.14.0")
 }
 
+tasks.named<Checkstyle>("checkstyleTest") {
+  // exclude generated classes
+  exclude("**/example/**")
+}
+
 val latestDepTest = findProperty("testLatestDeps") as Boolean
 protobuf {
   protoc {