Review fixes for opensearch-rest-3.0:javaagent (open-telemetry#17570)

Co-authored-by: otelbot <197425009+otelbot@users.noreply.github.com>

Author: otelbot[bot]

instrumentation/opensearch/opensearch-rest-3.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/opensearch/rest/v3_0/OpenSearchRestInstrumentationModule.java

@@ -24,7 +24,7 @@ public OpenSearchRestInstrumentationModule() {
 
   @Override
   public ElementMatcher.Junction<ClassLoader> classLoaderMatcher() {
-    // class introduced in 3.0.0
+    // added in 3.0.0
     return hasClassesNamed("org.opensearch.client.http.HttpUriRequestProducer");
   }
 

instrumentation/opensearch/opensearch-rest-3.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/opensearch/rest/v3_0/OpenSearchRestSingletons.java

@@ -35,6 +35,7 @@ public int getStatusCode() {
       }
 
       @Override
+      @Nullable
       public InetAddress getAddress() {
         return response.getHost().getAddress();
       }

instrumentation/opensearch/opensearch-rest-3.0/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/opensearch/rest/v3_0/RestClientInstrumentation.java

@@ -49,7 +49,7 @@ public void transform(TypeTransformer transformer) {
         getClass().getName() + "$PerformRequestAsyncAdvice");
   }
 
-  public static class AdviceScope {
+  public static final class AdviceScope {
     private final OpenSearchRestRequest otelRequest;
     private final Context parentContext;
     private final Context context;