[Build.Tasks] Use LogDebugMessage instead of LogWarning in ExtractAll() (#329)

The path-traversal skip message in Files.ExtractAll() used LogWarning,
but this is a diagnostic/informational message that should use
LogDebugMessage (MessageImportance.Low) instead.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: jonathanpeppers

src/Microsoft.Android.Build.BaseTasks/Files.cs

@@ -472,7 +472,7 @@ public static bool ExtractAll (ZipArchive zip, string destination, Action<int, i
 					var fullName = modifyCallback?.Invoke (entry.FullName) ?? entry.FullName;
 					var outfile = Path.GetFullPath (Path.Combine (destination, fullName));
 					if (!outfile.StartsWith (fullDestination, StringComparison.OrdinalIgnoreCase)) {
-						log?.LogWarning ($"Skipping zip entry \"{entry.FullName}\" (resolved as \"{fullName}\") because it would extract outside the destination directory: \"{outfile}\".");
+						log?.LogDebugMessage ($"Skipping zip entry \"{entry.FullName}\" (resolved as \"{fullName}\") because it would extract outside the destination directory: \"{outfile}\".");
 						continue;
 					}
 					files.Add (outfile);