HarmonyOS List等滚动容器的scrollBar什么时候支持自定义样式，目前只支持宽度和颜色

@Entry  
@Component  
struct page240524145602071 {  
  private scroller: Scroller = new Scroller()  
  private arr: number[] = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15]  
  build() {  
    Column() {  
      Stack({ alignContent: Alignment.End }) {  
        Scroll(this.scroller) {  
          Flex({ direction: FlexDirection.Column }) {  
            ForEach(this.arr, (item: number) => {  
              Row() {  
                Text(item.toString())  
                  .width('80%')  
                  .height(60)  
                  .backgroundColor('#3366CC')  
                  .borderRadius(15)  
                  .fontSize(16)  
                  .textAlign(TextAlign.Center)  
                  .margin({ top: 5 })  
              }  
            }, (item: number) => item.toString())  
          }.margin({ right: 15 })  
        }  
        .width('90%')  
        .scrollBar(BarState.Off)  
        .scrollable(ScrollDirection.Vertical)  
  
        ScrollBar({ scroller: this.scroller, direction: ScrollBarDirection.Vertical, state: BarState.Auto }) {  
          Image($r('app.media.app_icon'))  
            .width(20)  
        }  
        .width(20)  
        .height(100)  
        // .backgroundColor('#ededed')  
        .backgroundImage($r('app.media.background'))  
        .backgroundImageSize({ width: 20, height: 100 })  
      }  
    }  
  }  
}