fix StorageFolder.GetItemsAsync on android

src/Android/Avalonia.Android/Platform/Storage/AndroidStorageItem.cs

@@ -138,7 +138,43 @@ internal class AndroidStorageFolder : AndroidStorageItem, IStorageBookmarkFolder
             return Array.Empty<IStorageItem>();
         }
 
-        using var javaFile = new JavaFile(Uri.Path!);
+        List<IStorageItem> files = new List<IStorageItem>();
+
+        var contentResolver = Activity.ContentResolver;
+        if (contentResolver == null)
+        {
+            return files;
+        }
+
+        var childrenUri = DocumentsContract.BuildChildDocumentsUriUsingTree(Uri!, DocumentsContract.GetTreeDocumentId(Uri));
+
+        var projection = new[]
+        {
+            DocumentsContract.Document.ColumnDocumentId,
+            DocumentsContract.Document.ColumnMimeType
+        };
+        if (childrenUri != null)
+        {
+            using var cursor = contentResolver.Query(childrenUri, projection, null, null, null);
+
+            if (cursor != null)
+                while (cursor.MoveToNext())
+                {
+                    var mime = cursor.GetString(1);
+                    var id = cursor.GetString(0);
+                    var uri = DocumentsContract.BuildDocumentUriUsingTree(Uri!, id);
+                    if (uri == null)
+                    {
+                        continue;
+                    }
+
+                    files.Add(mime == DocumentsContract.Document.MimeTypeDir ? new AndroidStorageFolder(Activity, uri, false) :
+                        new AndroidStorageFile(Activity, uri));
+                }
+        }
+
+        return files;
+    }
 
         // Java file represents files AND directories. Don't be confused.
         var files = await javaFile.ListFilesAsync().ConfigureAwait(false);