How to display a notification window during a call?

Question

Java

It is necessary to display a window during a call. That is, it should appear on top of the standard dialer.
How to do this is written in detail here: https://habr.com/ru/company/skbkontur/blog/243063/

But there is a problem, in Android >= 8 it does not work: our window is overlapped by the standard dialer window.
Question: is it possible to solve the problem on a new android without root?

Answer 1

Here they seem to have found a solution (one of the flags has changed):
https://github.com/Cleveroad/MusicBobber/issues/20
Upd.
And here's an example of a dynamic user permission request:
https://stackoverflow.com/a/47749566
Upd.
And the documentation says it all in plain text:
https://developer.android.com/reference/android/vi...