fix default music assets not loading

app/src/main/java/com/robtopx/geometryjump/LaunchUtils.kt

@@ -1,6 +1,8 @@
 package com.robtopx.geometryjump
 
+import android.content.pm.PackageInfo
 import android.content.pm.PackageManager
+import android.content.res.AssetManager
 import dalvik.system.BaseDexClassLoader
 import java.io.File
 
@@ -50,4 +52,12 @@ object LaunchUtils {
             false
         }
     }
+
+    fun addAssetsFromPackage(assetManager: AssetManager, packageInfo: PackageInfo) {
+        // this method is officially marked as deprecated but it is the only method we are allowed to reflect
+        // (the source recommends replacing with AssetManager.setApkAssets(ApkAssets[], boolean) lol)
+        val clazz = assetManager.javaClass
+        val aspMethod = clazz.getDeclaredMethod("addAssetPath", String::class.java)
+        aspMethod.invoke(assetManager, packageInfo.applicationInfo.sourceDir)
+    }
 }

app/src/main/java/dev/xyze/geodelauncher/GeometryDashActivity.kt

@@ -2,6 +2,7 @@ package dev.xyze.geodelauncher
 
 import android.content.Intent
 import android.content.pm.ActivityInfo
+import android.os.Build
 import android.os.Bundle
 import android.os.Environment
 import androidx.activity.ComponentActivity
@@ -42,6 +43,8 @@ class GeometryDashActivity : ComponentActivity(), Cocos2dxHelper.Cocos2dxHelperL
         val gdPackageInfo = packageManager.getPackageInfo(GJConstants.PACKAGE_NAME, 0)
         val gdNativeLibraryPath = "${gdPackageInfo.applicationInfo.nativeLibraryDir}/"
 
+        LaunchUtils.addAssetsFromPackage(assets, gdPackageInfo)
+
         LaunchUtils.addDirectoryToClassPath(gdNativeLibraryPath, classLoader)
 
         System.loadLibrary(GJConstants.FMOD_LIB_NAME)