I decided to clean a little my PC.
So I made 'fresh' installation of Redstone 4 (Windows 10, April 2018 update) and began to install latest releases: Java 10.0.2, Android Studio 3.1.3, B4A 8.30.
I used latest SDK tools package (4333796) and exactly this was a problem.
I installed all recommended software in SDK manager, but AVD manager did not want to create AVDs at all (and also didn't see AVDs, which I created in Android Studio).
I decided to install old sdk-tools (3859397, dated March 2017). AVD manager began to create AVD. But it did not want to see AVDs from Android Studio. After some experiments I found a solution - it's necessary to install corresponding system image in B4A SDK Manager.
For example, in Android Studio I created "Nexus 5X API 25" AVD. In B4A SDK manager it's necessary to install Google APIs Intel x86 Atom System image (Android 25).