remember size of file chooser dialogs (IDEADEV-42144)

platform/platform-impl/src/com/intellij/openapi/fileChooser/ex/FileChooserDialogImpl.java

@@ -513,4 +513,8 @@ public class FileChooserDialogImpl extends DialogWrapper implements FileChooserD
     setErrorText(null);
   }
 
+  @Override
+  protected String getDimensionServiceKey() {
+    return "FileChooserDialogImpl";
+  }
 }