[fix][client] Fix the startMessageId can't be respected as the ChunkM…

…essageID (#16154)

### Motivation

This is the same problem as when the consumer inclusive seeks the chunked message.

See more detail in [PIP-107](#12402)

### Modifications

* Use the first chunk message id as the startMessageId when creating the consumer/reader.

pulsar-broker/src/test/java/org/apache/pulsar/client/impl/MessageChunkingTest.java

@@ -520,6 +520,15 @@ public void testSeekChunkMessages() throws PulsarClientException {
             assertEquals(msgIds.get(i), msgAfterSeek.getMessageId());
         }
 
+        Reader<byte[]> reader = pulsarClient.newReader()
+                .topic(topicName)
+                .startMessageIdInclusive()
+                .startMessageId(msgIds.get(1))
+                .create();
+
+        Message<byte[]> readMsg = reader.readNext(5, TimeUnit.SECONDS);
+        assertEquals(msgIds.get(1), readMsg.getMessageId());
+
         consumer1.close();
         consumer2.close();
         producer.close();
@@ -549,5 +558,5 @@ private String createMessagePayload(int size) {
         }
         return str.toString();
     }
- 
+
 }

pulsar-client/src/main/java/org/apache/pulsar/client/impl/ConsumerImpl.java

@@ -249,7 +249,14 @@ protected ConsumerImpl(PulsarClientImpl client, String topic, ConsumerConfigurat
                 interceptors);
         this.consumerId = client.newConsumerId();
         this.subscriptionMode = conf.getSubscriptionMode();
-        this.startMessageId = startMessageId != null ? new BatchMessageIdImpl((MessageIdImpl) startMessageId) : null;
+        if (startMessageId != null) {
+            if (startMessageId instanceof ChunkMessageIdImpl) {
+                this.startMessageId = new BatchMessageIdImpl(
+                        ((ChunkMessageIdImpl) startMessageId).getFirstChunkMessageId());
+            } else {
+                this.startMessageId = new BatchMessageIdImpl((MessageIdImpl) startMessageId);
+            }
+        }
         this.initialStartMessageId = this.startMessageId;
         this.startMessageRollbackDurationInSec = startMessageRollbackDurationInSec;
         AVAILABLE_PERMITS_UPDATER.set(this, 0);