AsyncTask is deprecated in API 30 (Android 11)

[byunlee]

https://developer.android.com/reference/android/os/AsyncTask

Android documentation says:

This class was deprecated in API level 30.
Use the standard java.util.concurrent or Kotlin concurrency utilities instead.

I see AsyncTask being used in a few places. It should be replaced with something else.

[thomaszurkan-optimizely]

https://github.com/optimizely/android-sdk/releases/tag/3.10.0