mobile: on iOS stopping autorun tests doesn't work

[hellais]

I opened up the OONI Probe mobile app and I had some tests running, which I assumed were from background runs.

I went into the Running screen and tapped "Stop test" and nothing happened (the screen didn't change to "stopping tests" and the progress just kept moving forward). I tapped it a few times to no avail and waited some time to see if maybe it would eventually stop which it didn't.

In order to have it stop I had to force quit the application (swipe up).

I am assuming this autorun task had started since a while, since I have run tests automatically only when connected to power and my phone had not been connected to power in a while.

[aanorbel]

After initial analysis, the issue is caused by the system stops the background task but the proper events are not triggered to update the app state.

Clicking on the stop button has no effect since the task is essentially not running.

Some changes were made to fix background task errors and this error doesnt seem to be happening anymore.