OZG-6162 refactor string to constant

document-manager-server/src/main/java/de/ozgcloud/document/DocumentManagerConfiguration.java

@@ -41,12 +41,15 @@ import net.devh.boot.grpc.client.inject.GrpcClient;
 @Configuration
 public class DocumentManagerConfiguration {
 
+	private static final String GRPC_USER_MANAGER_NAME = "user-manager";
+	private static final String GRPC_COMMAND_MANAGER_NAME = "command-manager";
+
 	public static final String COMMAND_SERVICE_NAME = "bescheid_OzgCloudCommandService";
 	public static final String USER_PROFILE_SERVICE_NAME = "bescheid_OzgCloudUserProfileService";
 
-	@GrpcClient("command-manager")
+	@GrpcClient(GRPC_COMMAND_MANAGER_NAME)
 	private CommandServiceGrpc.CommandServiceBlockingStub commandServiceStub;
-	@GrpcClient("user-manager")
+	@GrpcClient(GRPC_USER_MANAGER_NAME)
 	private UserProfileServiceGrpc.UserProfileServiceBlockingStub userProfileServiceStub;
 
 	@Bean(COMMAND_SERVICE_NAME)