Bug: An error dialog may sometimes shown while using some school APIs

[Xanonymous-GitHub]

Describe the bug
The MsgDialog, which tells us about an error occurred, may sometimes shown after some operations.
After #173, we have added some ways to check if current session is still alive. But seems that there are still some possibilities that cause the Task to be failed.

To Reproduce
This is hard to be reproduced, since we can not sure when will it happened.
But maybe you can feel it like time-expiring cases, or some kinds of hijack session cases.
Anyway, just use the app or put it idle for some while, then the problem may occurred.

Expected behavior
All the exceptions which related to session failed, expired, etc should be automatically detected by App, and solved itself.

Smartphone (please complete the following information):

• Version 1.4.3

Additional context
Note that this issue may have a higher frequently happened rate in the IAB.
Try to find it there.