[tests] Ignore transient IO errors in on-device HTTP tests (#10962)

* Ignore transient SSL errors in on-device HTTP client handler tests
* Scope IOException check to HttpRequestException inner exceptions

Co-authored-by: Jonathan Peppers <jonathan.peppers@microsoft.com>

Author: Copilot

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

@@ -128,7 +128,20 @@ protected bool IgnoreIfConnectionFailed (AggregateException aex, out bool connec
 
 		bool IgnoreIfConnectionFailed (HttpRequestException hrex, out bool connectionFailed)
 		{
-			return IgnoreIfConnectionFailed (hrex?.InnerException as WebException, out connectionFailed);
+			connectionFailed = false;
+			if (hrex == null)
+				return false;
+
+			if (IgnoreIfConnectionFailed (hrex.InnerException as WebException, out connectionFailed))
+				return true;
+
+			if (hrex.InnerException is System.IO.IOException ioEx) {
+				connectionFailed = true;
+				Assert.Ignore ($"Ignoring transient IO error: {ioEx}");
+				return true;
+			}
+
+			return false;
 		}
 
 		bool IgnoreIfConnectionFailed (WebException wex, out bool connectionFailed)
@@ -168,6 +181,7 @@ bool IgnoreIfSocketException (Exception ex, out bool connectionFailed)
 			}
 			return false;
 		}
+
 	}
 
 	[Category ("AndroidClientHandler")]