@Konstantin Ay Thanks for your patience on this. I had quickly checked with Azure Communication service engineering team on this and sharing the below.
ACS team has confirmed that this feature is in GA now, please try the latest GA version library below and let us know if you are facing any issues.
https://mvnrepository.com/artifact/com.azure.android/azure-communication-calling/2.12.0
Regarding the documentation update, I am following with content author internally on this.