HarmonyOS 鸿蒙Next 设置UserAgent时，ArkWeb/{ArkWeb VersionCode} {Mobile} 如何获取？

目前ArkWeb版本号是通过获取全部userAgent字符串并从中提取出ArkWeb版本号获取的，其他方式暂时不支持

// xxx.ets

import { webview } from '[@kit](/user/kit).ArkWeb';

import { BusinessError } from '[@kit](/user/kit).BasicServicesKit';

[@Entry](/user/Entry)

[@Component](/user/Component)

struct WebComponent {

  controller: webview.WebviewController = new webview.WebviewController();

  [@State](/user/State) userAgent: string = '';

  build() {

    Column() {

      Button('getCustomUserAgent')

        .onClick(() => {

          try {

            this.userAgent = this.controller.getCustomUserAgent();

            console.log("userAgent: " + this.userAgent);

          } catch (error) {

            console.error(`ErrorCode: ${(error as BusinessError).code},  Message: ${(error as BusinessError).message}`);

          }

        })

      Web({ src: 'www.example.com', controller: this.controller })

    }

  }

}