ios微信客户端升级7.0.4后， openDocument回调显示成功却不展示

• 当前 Bug 的表现（可附上截图）

• 预期表现

openDocument成功后打开对应文档

• 复现路径

• 提供一个最简复现 Demo

wx.downloadFile({     url: 'xxx.xxxx.com/Authorization=' + app.globalData.token + '?id=' + id,     success(res) {     let FileSys = wx.getFileSystemManager();     FileSys.saveFile({       tempFilePath: res.tempFilePath,          success: function (res) {          wx.openDocument({                     filePath: res.savedFilePath,                     success: function(res) {                       console.log('openDocument', res);                     },                     fail: function (res) {                       wx.showToast({                         title: '文件打开失败',                         icon: 'none'                       })                     }                   });          }     })   }          })