kafka-node: fix message value to be string or Buffer (#23201)

types/kafka-node/index.d.ts

@@ -3,6 +3,8 @@
 // Definitions by: Daniel Imrie-Situnayake <https://github.com/dansitu>, Bill <https://github.com/bkim54>, Michael Haan <https://github.com/sfrooster>, Amiram Korach <https://github.com/amiram>
 // Definitions: https://github.com/DefinitelyTyped/DefinitelyTyped
 
+/// <reference types="node" />
+
 // # Classes
 export class Client {
     constructor(connectionString: string, clientId?: string, options?: ZKOptions, noBatchOptions?: AckBatchOptions, sslOptions?: any);
@@ -88,24 +90,24 @@ export class Offset {
 }
 
 export class KeyedMessage {
-    constructor(key: string, message: string);
+    constructor(key: string, value: string | Buffer);
 }
 
 // # Interfaces
 
 export interface Message {
-  topic: string;
-  value: string;
-  offset?: number;
-  partition?: number;
-  highWaterOffset?: number;
-  key?: string;
-}
+    topic: string;
+    value: string | Buffer;
+    offset?: number;
+    partition?: number;
+    highWaterOffset?: number;
+    key?: string;
+  }
 
 export interface ProducerOptions {
-  requireAcks?: number;
-  ackTimeoutMs?: number;
-  partitionerType?: number;
+    requireAcks?: number;
+    ackTimeoutMs?: number;
+    partitionerType?: number;
 }
 
 export interface KafkaClientOptions {