Not support with visionOS #52

Description of the bug

An error occurs when running the code below.

[[UnityGetMainWindow() rootViewController]  presentViewController:filePicker animated:YES completion:nil];

No scene size for <UnityDefaultViewController: 0x15f5f3310>
StopwatchSupport/XRSheetHostManager.swift:99: Fatal error: No source scene for <UIWindow: 0x15f5f1c50; frame = (0 0; 1366 1024); gestureRecognizers = <NSArray: 0x281a2d320>; layer = <UIWindowLayer: 0x281a2d080>>

Platform specs

Please provide the following info if this is a Unity 3D repository.

• Unity version: 2023.3.18f1
• Platform: visionOS 1.0.3
• Device: Apple Vision Pro

Additional info

Please check Logcat (Android) or Xcode console (iOS) for any meaningful error messages and include them here.