Only add ReadTimeoutHandler to Netty4 http pipeline if not a noop (#91307)

No need to add this for the (default) case of no http read timeout,
it just adds needless overhead and makes profiling harder to read.

modules/transport-netty4/src/main/java/org/elasticsearch/http/netty4/Netty4HttpServerTransport.java

@@ -307,21 +307,25 @@ public class Netty4HttpServerTransport extends AbstractHttpServerTransport {
         protected void initChannel(Channel ch) throws Exception {
             Netty4HttpChannel nettyHttpChannel = new Netty4HttpChannel(ch);
             ch.attr(HTTP_CHANNEL_KEY).set(nettyHttpChannel);
-            ch.pipeline().addLast("chunked_writer", new Netty4WriteThrottlingHandler(transport.getThreadPool().getThreadContext()));
-            ch.pipeline().addLast("byte_buf_sizer", NettyByteBufSizer.INSTANCE);
-            ch.pipeline().addLast("read_timeout", new ReadTimeoutHandler(transport.readTimeoutMillis, TimeUnit.MILLISECONDS));
+            ch.pipeline()
+                .addLast("chunked_writer", new Netty4WriteThrottlingHandler(transport.getThreadPool().getThreadContext()))
+                .addLast("byte_buf_sizer", NettyByteBufSizer.INSTANCE);
+            if (transport.readTimeoutMillis > 0) {
+                ch.pipeline().addLast("read_timeout", new ReadTimeoutHandler(transport.readTimeoutMillis, TimeUnit.MILLISECONDS));
+            }
             final HttpRequestDecoder decoder = new HttpRequestDecoder(
                 handlingSettings.maxInitialLineLength(),
                 handlingSettings.maxHeaderSize(),
                 handlingSettings.maxChunkSize()
             );
             decoder.setCumulator(ByteToMessageDecoder.COMPOSITE_CUMULATOR);
-            ch.pipeline().addLast("decoder", decoder);
-            ch.pipeline().addLast("decoder_compress", new HttpContentDecompressor());
-            ch.pipeline().addLast("encoder", new HttpResponseEncoder());
             final HttpObjectAggregator aggregator = new HttpObjectAggregator(handlingSettings.maxContentLength());
             aggregator.setMaxCumulationBufferComponents(transport.maxCompositeBufferComponents);
-            ch.pipeline().addLast("aggregator", aggregator);
+            ch.pipeline()
+                .addLast("decoder", decoder)
+                .addLast("decoder_compress", new HttpContentDecompressor())
+                .addLast("encoder", new HttpResponseEncoder())
+                .addLast("aggregator", aggregator);
             if (handlingSettings.compression()) {
                 ch.pipeline().addLast("encoder_compress", new HttpContentCompressor(handlingSettings.compressionLevel()));
             }