Application freezes showing uPort screen

[BessMark]

Describe the bug
Application freezes showing uPort screen on second launch after "back" button is used to exit application.

To Reproduce
Steps to reproduce the behavior:

1. Install and open uPort application;
2. Login and create in uPort uportlandia city id;
3. Swap right to left on smartphone screen
4. Application is minimized, but once you want to restore it the UPort screen is shown.
   It is possible to open application again only after the phone being forced to stop or gets rebooted.

Expected behavior
After the lunching it should be open main application screen

Mobile phone:

• OS: Android version: 9 Pkg 1.181121.001 with Global MIUI ver 10.2.13.0
• Uport version: 1.6.473

Additional context
Add any other context about the problem here.

[vlmold]

+1