Adjust use of Deprecated Netty API (#42613)

* With the recent upgrade to Netty 4.1.36 this method became deprecated and I made the advised change to fix the deprecation

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

@@ -23,8 +23,8 @@ import io.netty.bootstrap.ServerBootstrap;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
-import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.FixedRecvByteBufAllocator;
@@ -351,7 +351,7 @@ public class Netty4HttpServerTransport extends AbstractHttpServerTransport {
     }
 
     @ChannelHandler.Sharable
-    private static class ServerChannelExceptionHandler extends ChannelHandlerAdapter {
+    private static class ServerChannelExceptionHandler extends ChannelInboundHandlerAdapter {
 
         private final Netty4HttpServerTransport transport;
 

modules/transport-netty4/src/main/java/org/elasticsearch/transport/netty4/Netty4Transport.java

@@ -25,8 +25,8 @@ import io.netty.channel.AdaptiveRecvByteBufAllocator;
 import io.netty.channel.Channel;
 import io.netty.channel.ChannelFuture;
 import io.netty.channel.ChannelHandler;
-import io.netty.channel.ChannelHandlerAdapter;
 import io.netty.channel.ChannelHandlerContext;
+import io.netty.channel.ChannelInboundHandlerAdapter;
 import io.netty.channel.ChannelInitializer;
 import io.netty.channel.ChannelOption;
 import io.netty.channel.FixedRecvByteBufAllocator;
@@ -315,7 +315,7 @@ public class Netty4Transport extends TcpTransport {
     }
 
     @ChannelHandler.Sharable
-    private class ServerChannelExceptionHandler extends ChannelHandlerAdapter {
+    private class ServerChannelExceptionHandler extends ChannelInboundHandlerAdapter {
 
         @Override
         public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {