fix Android XAGMM7009 by removing OsuApplication subclass

Agent-Logs-Url: https://github.com/winnerspiros/osu/sessions/c1769bd6-c639-44bc-b1e9-1eba8acf7081

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

Author: Copilot

osu.Android/AndroidManifest.xml

@@ -1,7 +1,7 @@
 <?xml version='1.0' encoding='utf-8'?>
 <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="sh.ppy.osulazer" android:installLocation="auto">
 	<uses-sdk android:minSdkVersion="33" android:targetSdkVersion="36" />
-	<application>
+	<application android:allowBackup="true" android:supportsRtl="true" android:label="osu!" android:icon="@mipmap/ic_launcher" android:roundIcon="@mipmap/ic_launcher" android:largeHeap="true" android:hardwareAccelerated="true" android:extractNativeLibs="false">
         <provider android:name="androidx.core.content.FileProvider" android:authorities="sh.ppy.osulazer.fileprovider" android:grantUriPermissions="true" android:exported="false">
             <meta-data android:name="android.support.FILE_PROVIDER_PATHS" android:resource="@xml/filepaths" />
         </provider>

osu.Android/CrashDiagnostics.cs

@@ -40,11 +40,11 @@ internal static class CrashDiagnostics
 
         /// <summary>
         /// Installs the native crash handler against the internal-storage log path, drops the
-        /// sentinel, and writes the first "I am alive" marker. Idempotent — safe to call from
-        /// both <see cref="Application.OnCreate"/> and <see cref="Activity.OnCreate(Bundle)"/>;
-        /// the underlying handler dedupes via its own <c>g_installed</c> flag.
+        /// sentinel, and writes the first "I am alive" marker. Idempotent — safe to call
+        /// repeatedly from <c>Activity.OnCreate</c>; the underlying handler dedupes
+        /// via its own <c>g_installed</c> flag.
         /// </summary>
-        /// <param name="context">Any <see cref="Context"/> — typically the Application or Activity.</param>
+        /// <param name="context">Any <see cref="Context"/> — typically the host Activity.</param>
         public static void InstallNativeHandler(Context context)
         {
             try

osu.Android/OsuApplication.cs

@@ -86,10 +86,11 @@ protected override void OnCreate(Bundle? savedInstanceState)
             // Crash diagnostics first. The native handler write target is internal storage
             // (FilesDir/native_crash.log); a one-shot mirror copies it to external storage
             // here on the *next* normal startup so the user can pull it without root.
-            // OsuApplication.OnCreate already installed both the native handler and the
-            // managed exception hooks — these calls are idempotent safety nets that cover
-            // the (vanishingly unlikely) case where the activity is created without our
-            // Application subclass having run first.
+            // We do NOT have a custom Android.App.Application subclass — ppy.osu.Framework.Android
+            // already declares `[assembly: Application]`, so adding our own `[Application]`
+            // class would trigger XAGMM7009 at manifest-merge time. The activity is the
+            // earliest managed entry point we own; install both hooks at the very top of
+            // OnCreate so any crash from this point onward lands in `native_crash.log`.
             CrashDiagnostics.InstallNativeHandler(this);
             CrashDiagnostics.InstallManagedExceptionHooks();
             CrashDiagnostics.WriteAliveMarker("Activity.OnCreate entry");