Add logging and const for test port as requested in code review

Co-authored-by: jonathanpeppers <840039+jonathanpeppers@users.noreply.github.com>

Author: Copilot

tests/Mono.Android-Tests/Mono.Android-Tests/Xamarin.Android.Net/AndroidMessageHandlerTests.cs

@@ -344,8 +344,9 @@ private static X509Certificate2 BuildClientCertificate ()
 		[Test]
 		public async Task HttpContentStreamIsRewoundAfterCancellation ()
 		{
+			const int testPort = 47664;
 			using var listener = new HttpListener ();
-			listener.Prefixes.Add ("http://+:47664/");
+			listener.Prefixes.Add ($"http://+:{testPort}/");
 			listener.Start ();
 
 			// Handle the first request - simulate a slow server to allow cancellation
@@ -357,22 +358,24 @@ public async Task HttpContentStreamIsRewoundAfterCancellation ()
 					while (ctx.Request.InputStream.Read (buffer, 0, buffer.Length) > 0) {
 						System.Threading.Thread.Sleep (100); // Slow down to allow cancellation
 					}
-				} catch {
+				} catch (Exception ex) {
 					// Expected when connection is cancelled
+					Console.WriteLine ($"Exception while reading request body: {ex}");
 				}
 				try {
 					ctx.Response.StatusCode = 200;
 					ctx.Response.Close ();
-				} catch {
+				} catch (Exception ex) {
 					// Connection may already be closed
+					Console.WriteLine ($"Exception while closing response: {ex}");
 				}
 			}, null);
 
 			var tcs = new System.Threading.CancellationTokenSource ();
 			tcs.CancelAfter (500); // Cancel after 500ms
 			var client = new HttpClient (new AndroidMessageHandler ());
 			var byc = new ByteArrayContent (new byte[1_000_000]); // 1 MB of data
-			var request = new HttpRequestMessage (HttpMethod.Post, "http://localhost:47664/") { Content = byc };
+			var request = new HttpRequestMessage (HttpMethod.Post, $"http://localhost:{testPort}/") { Content = byc };
 
 			var stream = await byc.ReadAsStreamAsync ();
 			var positionBefore = stream.Position;
@@ -382,9 +385,10 @@ public async Task HttpContentStreamIsRewoundAfterCancellation ()
 			try {
 				await client.SendAsync (request, tcs.Token).ConfigureAwait (false);
 				// If we get here without exception, that's also OK for this test
-			} catch (Exception) {
+			} catch (Exception ex) {
 				// Expected - cancellation or connection error
 				// We catch all exceptions to ensure the test doesn't fail due to unhandled exceptions
+				Console.WriteLine ($"Exception during first request (expected): {ex}");
 				exceptionThrown = true;
 			}
 
@@ -393,10 +397,9 @@ public async Task HttpContentStreamIsRewoundAfterCancellation ()
 			var positionAfter = stream2.Position;
 			Assert.AreEqual (0, positionAfter, "Stream position should be 0 after failed request (stream should be rewound)");
 
-
 			// Only proceed with second request if we actually got an exception (test scenario succeeded)
 			if (exceptionThrown) {
-				var request2 = new HttpRequestMessage (HttpMethod.Post, "http://localhost:47664/") { Content = byc };
+				var request2 = new HttpRequestMessage (HttpMethod.Post, $"http://localhost:{testPort}/") { Content = byc };
 
 				// Set up listener for second request
 				listener.BeginGetContext (ar => {
@@ -411,7 +414,6 @@ public async Task HttpContentStreamIsRewoundAfterCancellation ()
 				var stream3 = await byc.ReadAsStreamAsync ();
 				var positionFinal = stream3.Position;
 				Assert.AreEqual (0, positionFinal, "Stream position should be 0 after successful request");
-
 			}
 
 			listener.Close ();