Fix compilation warnings and spotless

Author: JonasKunz

instrumentation/armeria/armeria-grpc-1.14/javaagent/src/main/java/io/opentelemetry/javaagent/instrumentation/armeria/grpc/v1_14/ArmeriaServerCallInstrumentation.java

@@ -10,7 +10,6 @@
 
 import com.linecorp.armeria.server.ServiceRequestContext;
 import io.grpc.ServerCall;
-import io.opentelemetry.instrumentation.api.util.VirtualField;
 import io.opentelemetry.instrumentation.grpc.v1_6.GrpcAuthorityStorage;
 import io.opentelemetry.javaagent.extension.instrumentation.TypeInstrumentation;
 import io.opentelemetry.javaagent.extension.instrumentation.TypeTransformer;

instrumentation/grpc-1.6/library/src/main/java/io/opentelemetry/instrumentation/grpc/v1_6/GrpcAuthorityStorage.java

@@ -1,17 +1,24 @@
+/*
+ * Copyright The OpenTelemetry Authors
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
 package io.opentelemetry.instrumentation.grpc.v1_6;
 
 import io.grpc.ServerCall;
 import io.opentelemetry.instrumentation.api.util.VirtualField;
 
 /**
- * In case a {@link ServerCall} implementation does not implement {@link ServerCall#getAuthority()} like armeria,
- * this utility class should be used to provide the authority instead
+ * In case a {@link ServerCall} implementation does not implement {@link ServerCall#getAuthority()}
+ * like armeria, this utility class should be used to provide the authority instead
  */
 public class GrpcAuthorityStorage {
 
   private static final VirtualField<ServerCall<?, ?>, String> AUTHORITY_FIELD =
       VirtualField.find(ServerCall.class, String.class);
 
+  private GrpcAuthorityStorage() {}
+
   public static void setAuthority(ServerCall<?, ?> call, String authority) {
     AUTHORITY_FIELD.set(call, authority);
   }