Make Kestrel default to HTTP/1 and /2. (#50243)

Author: adityamandaleeka

src/Servers/Kestrel/Core/src/ListenOptions.cs

@@ -16,7 +16,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core;
 /// </summary>
 public class ListenOptions : IConnectionBuilder, IMultiplexedConnectionBuilder
 {
-    internal const HttpProtocols DefaultHttpProtocols = HttpProtocols.Http1AndHttp2AndHttp3;
+    internal const HttpProtocols DefaultHttpProtocols = HttpProtocols.Http1AndHttp2;
 
     private readonly List<Func<ConnectionDelegate, ConnectionDelegate>> _middleware = new List<Func<ConnectionDelegate, ConnectionDelegate>>();
     private readonly List<Func<MultiplexedConnectionDelegate, MultiplexedConnectionDelegate>> _multiplexedMiddleware = new List<Func<MultiplexedConnectionDelegate, MultiplexedConnectionDelegate>>();