[Android] Agent crashes when refresh token is expired

[milanperera]

Description:
When refresh token is expired, agent detects it and prompts the user to re-login to fetch new token pair. However, when the notification is tapped, the agent gets crashed.

Affected Product Version:
Android agent v3.1.24, IoTS-310

Steps to reproduce:
Enroll a device as BYOD work profile
Decrease the token expiry time of access token and refresh token in identity.xml
Then set the device to 'airplane' mode and wait until refresh token gets expired.
Switch off the airplane mode and connect the device to the network.