Description of problem: If user1 wants user2 to be able to display on his screen, the xhost command enables user1 to permit this; I cannot find any equivalent allowing user2 to play audio on user1's audio output.

Version-Release number of selected component (if applicable):

pipewire-0.3.47-2.el9_0.x86_64

How reproducible: (Always)

Steps to Reproduce:
1. login to display (and audio) as user1
2. xhost +si:localuser:user2 (thus giving user2 permission to access display)
3. su - user2
4. invoke a program that plays audio (and that works if step 3 is omitted); I tried both vlc and firefox with same result.

Actual results:

Audio output failed:
The audio device "default" could not be used:
Host is down.

Expected results:

Sound played on user1's audio output.

Additional info:

This used to work in 8.6 before upgrade to 9.0 . Moreover the sockets

./run/user/1000/pipewire-0
./run/user/1000/pulse/native

both are readable and writeable by both user1 and user2.