HarmonyOS 播控中心的时间比AVPlayer获取到的时间要少1s

可以参考一下，这里视频界面时长的数据来源和播控中心时长数据来源都是用的avPlayer.duration。

case 'prepared': // prepare调用成功后上报该状态机
console.info('AVPlayerDemo AVPlayer state prepared called.');
this.flag = true;
this.durationTime = Math.floor(avPlayer.duration / 1000);
this.durationStringTime = this.secondToTime(this.durationTime);
// avPlayer.loop = true;
avPlayer.setSpeed(media.PlaybackSpeed.SPEED_FORWARD_1_00_X)
avPlayer.seek(1, media.SeekMode.SEEK_PREV_SYNC)
await this.startAVSession();
break;

async startAVSession() {
  if (!this.currentAVSession) {
    console.error('AVPlayerDemo currentAVSession is undefined.')
    return;
  }
  let metadata: avSession.AVMetadata = this.generateAVMetadata();
  await this.currentAVSession.setAVMetadata(metadata).then(() => {
    console.info(`AVPlayerDemo SetAVMetadata successfully`);
  }).catch((err: BusinessError) => {
    console.error(`AVPlayerDemo SetAVMetadata BusinessError: code: ${err.code}, message: ${err.message}`);
  });
  this.playbackState.state = avSession.PlaybackState.PLAYBACK_STATE_PREPARE;
  this.playbackState.duration = this.avPlayer?.duration;
  this.currentAVSession.setAVPlaybackState(this.playbackState);
  // 通过按钮申请长时任务
  this.startContinuousTask();
  this.currentAVSession.getController().then((avcontroller: avSession.AVSessionController) => {
    this.avsessionController = avcontroller;
    console.info(`AVPlayerDemo GetController : SUCCESS : sessionid : ${avcontroller.sessionId}`);
  }).catch((err: BusinessError) => {
    console.error(`AVPlayerDemo GetController BusinessError: code: ${err.code}, message: ${err.message}`);
  });
  await this.currentAVSession.activate().then(() => {
    console.info(`AVPlayerDemo Activate : SUCCESS `);
  }).catch((err: BusinessError) => {
    console.error(`AVPlayerDemo Activate BusinessError: code: ${err.code}, message: ${err.message}`);
  });
}

private generateAVMetadata() {
  let previousIndex = this.addStepIndex(-1);
  let nextIndex = this.addStepIndex(1);
  let metadata: avSession.AVMetadata = {
    assetId: `${this.sourceFiles[this.currentIndex].fd}`, // 必须，媒体ID。歌曲的唯一标识，由应用自定义。
    title: `${this.sourceFiles[this.currentIndex].fd}`, // 标题
    artist: `艺术家${this.currentIndex}`, // 艺术家
    author: `专辑作者${this.currentIndex}`, // 专辑作者
    album: `专辑名称${this.currentIndex}`, // 专辑名称
    writer: `词作者${this.currentIndex}`, // 词作者
    composer: `作曲者${this.currentIndex}`, // 作曲者
    duration: this.avPlayer?.duration, // 媒体时长，单位毫秒（ms）
    mediaImage: this.curPixelMap, // 图片的像素数据或者图片路径地址(本地路径或网络路径)
    publishDate: new Date(), // 发行日期
    subtitle: `子标题${this.currentIndex}`, // 子标题
    description: `媒体描述${this.currentIndex}`, // 媒体描述
    previousAssetId: `${this.sourceFiles[previousIndex].fd}`, // 上一首媒体ID
    nextAssetId: `${this.sourceFiles[nextIndex].fd}`, // 下一首媒体ID
  };
  return metadata;
}