React to new HttpClient header size check dotnet#45811 (dotnet#45880)

Author: Tratcher

src/Servers/Kestrel/test/Interop.FunctionalTests/HttpClientHttp2InteropTests.cs

@@ -1342,7 +1342,6 @@ public async Task Settings_MaxFrameSize_Larger_Server(string scheme)
 
         [Theory]
         [MemberData(nameof(SupportedSchemes))]
-        [QuarantinedTest("https://github.com/dotnet/aspnetcore/issues/45811")]
         public async Task Settings_MaxHeaderListSize_Server(string scheme)
         {
             var oneKbString = new string('a', 1024);
@@ -1351,26 +1350,27 @@ public async Task Settings_MaxHeaderListSize_Server(string scheme)
                 {
                     ConfigureKestrel(webHostBuilder, scheme);
                     webHostBuilder.ConfigureServices(AddTestLogging)
-                    .Configure(app => app.Run(context => throw new NotImplementedException()));
+                    .Configure(app => app.Run(context => context.Response.WriteAsync("Hello World")));
                 });
             using var host = await hostBuilder.StartAsync().DefaultTimeout();
 
             var url = host.MakeUrl(scheme);
 
             using var client = CreateClient();
-            // There's no point in waiting for the settings to sync, the client doesn't check the header list size setting.
-            // https://github.com/dotnet/runtime/blob/48a78bfa13e9c710851690621fc2c0fe1637802c/src/libraries/System.Net.Http/src/System/Net/Http/SocketsHttpHandler/Http2Connection.cs#L467-L494
+            // Send an initial request to ensure the settings get synced before the real test.
+            var responseBody = await client.GetStringAsync(url).DefaultTimeout();
+            Assert.Equal("Hello World", responseBody);
 
             var request = CreateRequestMessage(HttpMethod.Get, url, content: null);
             // The default size limit is 32kb.
             for (var i = 0; i < 33; i++)
             {
                 request.Headers.Add("header" + i, oneKbString + i);
             }
-            var response = await client.SendAsync(request).DefaultTimeout();
-            await host.StopAsync().DefaultTimeout();
+            var ex = await Assert.ThrowsAsync<HttpRequestException>(() => client.SendAsync(request).DefaultTimeout());
+            Assert.Equal("The HTTP request headers length exceeded the server limit of 32768 bytes.", ex.Message);
 
-            Assert.Equal(HttpStatusCode.RequestHeaderFieldsTooLarge, response.StatusCode);
+            await host.StopAsync().DefaultTimeout();
         }
 
         [Theory]