Window flag: special flag to let windows be shown when the screen is locked. This will let application windows take precedence over key guard or any other lock screens. Can be used with WindowManagerFlags.KeepScreenOn to turn screen on and display windows directly before showing the key guard window. Can be used with WindowManagerFlags.DismissKeyguard to automatically fully dismisss non-secure keyguards. This flag only applies to the top-most full-screen window.