Move away from AsyncTask

[jobot0]

Is your feature request related to a problem? Please describe.
The AsyncTask API is getting deprecated. However we're using it in the reporting process. We should move away to implement another solution.

Describe the solution you'd like
The documention suggests:

Use the standard java.util.concurrent or Kotlin concurrency utilities instead.

Both imply major changes. The second one would be a more modern solution.