Fix exception variable naming: rename 'fe' to 'e' for consistency

Agent-Logs-Url: https://github.com/winnerspiros/osu/sessions/0bf6f340-f206-4105-88e4-30e371bcfd12

Co-authored-by: winnerspiros <1675249+winnerspiros@users.noreply.github.com>

Author: Copilot

osu.Android/OsuGameActivity.cs

@@ -269,9 +269,9 @@ protected override void OnCreate(Bundle? savedInstanceState)
                         {
                             holder.SetFormat(Android.Graphics.Format.Rgba8888);
                         }
-                        catch (Exception fe)
+                        catch (Exception e)
                         {
-                            Debug.WriteLine($"[osu!] Failed to request RGBA8888 surface format: {fe.Message}");
+                            Debug.WriteLine($"[osu!] Failed to request RGBA8888 surface format: {e.Message}");
                         }
 
                         holder.AddCallback(this);