Dont compile the android classes on other targets.

source/funkin/external/android/CallbackUtil.hx

@@ -1,5 +1,6 @@
 package funkin.external.android;
 
+#if android
 import lime.system.JNI;
 import flixel.util.FlxSignal;
 
@@ -9,7 +10,6 @@ import flixel.util.FlxSignal;
 @:unreflective
 class CallbackUtil
 {
-  #if android
   /**
    * The result code for `DATA_FOLDER_CLOSED` activity.
    */
@@ -42,7 +42,6 @@ class CallbackUtil
       initCallBackJNI(new CallbackHandler());
     }
   }
-  #end
 }
 
 /**
@@ -50,7 +49,6 @@ class CallbackUtil
  */
 class CallbackHandler #if (lime >= "8.0.0") implements JNISafety #end
 {
-  #if android
   @:allow(funkin.external.android.CallbackUtil)
   function new():Void {}
 
@@ -68,5 +66,5 @@ class CallbackHandler #if (lime >= "8.0.0") implements JNISafety #end
   {
     if (CallbackUtil.onActivityResult != null) CallbackUtil.onActivityResult.dispatch(requestCode, resultCode);
   }
-  #end
 }
+#end

source/funkin/external/android/DataFolderUtil.hx

@@ -1,12 +1,12 @@
 package funkin.external.android;
 
+#if android
 /**
  * A Utility class to manage the Application's Data folder on Android.
  */
 @:unreflective
 class DataFolderUtil
 {
-  #if android
   /**
    * Opens the data folder on an Android device using JNI.
    */
@@ -19,5 +19,5 @@ class DataFolderUtil
       openDataFolderJNI(CallbackUtil.DATA_FOLDER_CLOSED);
     }
   }
-  #end
 }
+#end

source/funkin/external/android/ScreenUtil.hx

@@ -1,5 +1,6 @@
 package funkin.external.android;
 
+#if android
 import lime.math.Rectangle;
 import lime.system.JNI;
 
@@ -9,7 +10,6 @@ import lime.system.JNI;
 @:unreflective
 class ScreenUtil
 {
-  #if android
   /**
    * Retrieves the dimensions of display cutouts (such as notches) on Android devices.
    *
@@ -48,5 +48,5 @@ class ScreenUtil
 
     return [];
   }
-  #end
 }
+#end