No warning to users if they select "while using the app" or "only this time" for location permissions.

[e-mcbride]

Description of the bug

How would you shortly summarise the issue?

As expected, if the user does not select "always allow" location services, then the application does not work. However, there is no user-side notification that the application will not work without "always allow" turned on for location services. So the user could be unaware that they need to change permissions for the app to work.

To Reproduce

What steps did you perform which led to this issue?

1. Run the application in Expo Go client on Android emulator
2. Press the "Grant permission" button on the application
3. When the app asks for location permissions, select "while using the app" or "only this time". The app navigates to the next page (where users can click "Start tracking").

Expected behavior

What did you expect to have happened?

I guess I didn't expect this to happen, but if the user selects "while using the app" instead of "always allow", then they should receive some sort of warning that the app will not work properly if "always allow" is not turned on.

Actual behavior

What did it actually result in?

• Error thrown: "Unhandled promise rejection: Error: Not authorized to use background location services".
• The "Start tracking" button does not work for the user, and there is no indication to the user of why the buttons are not working.
• If the user presses "Start tracking", then the same error is thrown again.

Additional context

Can you further explain the issue? E.g., information about version/environment or screenshots.

Tested on Expo Go client using Android Studio Virtual Devices. Tested on Android 10.0 and 11.0.

I also tested this on a physical iPhone 8 (iOS 14.4) using Expo Go client and had the same result. However, the Expo Go client cannot ask for permission to "always allow" location on iOS. So I have been unable to test how the "always allow" option works on iOS.