DraggableScrollbar for ListView Inside SingleChildScrollView

Using DraggableScrollBar for ListView (with width 1000) inside Horizontal SingleChildScrollBarView, the scrollbar appears only after scrolling horizontally to the end of list.

```
SingleChildScrollView(
scrollDirection: Axis.horizontal,
controller: _horizontalScrollController,
child: SizedBox(
width: BaseViewDataWidget.of(context).getWidth(),
child: DraggableScrollbar.semicircle(
controller: _listViewVerticalController,
child: ListView.builder(
itemCount: globals.recordCount,
itemExtent: 100,
controller: _listViewVerticalController,
itemBuilder: (context, index) {
return RecordWidget(index, offsetStream, _horizontalScrollController);
}),
),
),
)
```