Use explicit int cast for GameMode comparison to be clear about Android API int comparison

Co-authored-by: winnerspiros <1675249+winnerspiros@users.noreply.github.com>
Agent-Logs-Url: https://github.com/winnerspiros/osu/sessions/75739364-5690-4028-9d88-98f465b77bbc

Author: Copilot

osu.Android/OsuGameActivity.cs

@@ -134,7 +134,7 @@ protected override void OnResume()
 
                     if (gameManager != null)
                     {
-                        bool isPerformanceMode = (GameMode)gameManager.GameMode == GameMode.Performance;
+                        bool isPerformanceMode = gameManager.GameMode == (int)GameMode.Performance;
                         ApplyPerformanceOptimizations(isPerformanceMode);
                     }
                 }