set cumulator in the constructor

Author: sergiitk

netty/src/main/java/io/grpc/netty/GrpcHttp2ConnectionHandler.java

@@ -32,10 +32,6 @@
 @Internal
 public abstract class GrpcHttp2ConnectionHandler extends Http2ConnectionHandler {
 
-  {
-    setCumulator(COMPOSITE_CUMULATOR);
-  }
-
   @Nullable
   protected final ChannelPromise channelUnused;
 
@@ -46,6 +42,7 @@ protected GrpcHttp2ConnectionHandler(
       Http2Settings initialSettings) {
     super(decoder, encoder, initialSettings);
     this.channelUnused = channelUnused;
+    setCumulator(COMPOSITE_CUMULATOR);
   }
 
   /**