(#50) Fix bug by using projection var (computed columns) rather raw columns

Author: LaksCastro

android/src/main/kotlin/io/lakscastro/sharedstorage/storageaccessframework/lib/DocumentCommon.kt

@@ -201,7 +201,7 @@ fun traverseDirectoryEntries(
       while (cursor.moveToNext()) {
         val data = mutableMapOf<String, Any>()
 
-        for (column in columns) {
+        for (column in projection) {
           data[column] = cursorHandlerOf(typeOfColumn(column)!!)(
             cursor,
             cursor.getColumnIndexOrThrow(column)

example/lib/screens/folder_files/folder_file_list.dart

@@ -159,7 +159,7 @@ class _FolderFileListState extends State<FolderFileList> {
       DocumentFileColumn.displayName,
       DocumentFileColumn.size,
       DocumentFileColumn.lastModified,
-      DocumentFileColumn.id,
+      // DocumentFileColumn.id,
       DocumentFileColumn.mimeType,
     ];