Your UsbDetector - is a miracle, really.
As a result, after around 5 seconds after usb drive attached, video on my usb drive starts to play automatically. As I understand, it will not work after particular version of Android, but Android 7 allow to do that. 8 - no. My device controlled by Android 7 (single-board computer), so I solved this part of my issue, thank you very much.
Btw, it worked on Android TV too (if version below 8)