HarmonyOS 多个网络请求并发执行，等所有网络请求都返回后再执行UI刷新的示例

参考demo：

let promise1 = this.testPromiseImp(101)
let promise2 = this.testPromiseImp(102)
let promise3 = this.testPromiseImp(103)
let promise4 = this.testPromiseImp(104)
let promise5 = this.testPromiseImp(105)
Promise.all([promise1,promise2,promise3,promise4,promise5]).then(()=>{
  LogUtils.info(TAG,"并发完成")
})

private testPromiseImp(index:number):Promise<void>{
  return new Promise((resolve,reject)=>{
  let time = Date.now()
  console.info(`test info: ${JSON.stringify("testPromiseImp index start :"+index)}.`);
setTimeout(()=>{
  let timeEnd = Date.now()
  console.info(`test info: ${JSON.stringify("===>testPromiseImp index end :"+index+" 耗时："+(timeEnd-time))}.`);
  resolve()
},1000)
})
}