HarmonyOS webview打开HarmonyOS网页（如华为官网），需要设置终端UA

webview打开华为官网，需要设置终端UA，希望可以固化到Webview。

import web_webview from '@ohos.web.webview';
@Entry
@Component
struct Index {
  controller: web_webview.WebviewController = new web_webview.WebviewController();
  build() {
    Column() {
      Web({ src: "xxx", controller: this.controller })
        .onControllerAttached(() => {
          this.controller.setCustomUserAgent('Mozilla/5.0 (Linux; 9; VRD-AL10; HMSCore 6.3.0.331) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/99.0.4844.88 HuaweiBrowser/12.0.4.1 Mobile Safari/537.36')
        })
    }
    .width("100%")
    .height("100%")
  }
}