fix #4427

src/csharp/Grpc.Core/Internal/AsyncCallServer.cs

@@ -193,16 +193,6 @@ namespace Grpc.Core.Internal
             lock (myLock)
             {
                 finished = true;
-
-                if (cancelled)
-                {
-                    // Once we cancel, we don't have to care that much 
-                    // about reads and writes.
-
-                    // TODO(jtattermusch): is this still necessary?
-                    Cancel();
-                }
-
                 ReleaseResourcesIfPossible();
             }
             // TODO(jtattermusch): handle error

src/csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs

@@ -140,14 +140,12 @@ namespace Grpc.IntegrationTesting
         }
 
         [Test]
-        [Ignore("TODO: see #4427")]
         public async Task StatusCodeAndMessage()
         {
             await InteropClient.RunStatusCodeAndMessageAsync(client);
         }
 
         [Test]
-        [Ignore("TODO: see #4427")]
         public void UnimplementedMethod()
         {
             InteropClient.RunUnimplementedMethod(UnimplementedService.NewClient(channel));