snap-confine: extract helper from sc_join_preserved_{per_user,}_ns
The tiobe quality check found that we have some duplicated code in sc_join_preserved_ns() and sc_join_preserved_per_user_ns().
Given that the code is relatively nested and important this commit extracts two common helpers that will fix most of the duplication and makes the code also (IMHO) more readable.
tests: fix error in gadget-config-defaults-to-snaps test (#13033)
* Fix error in gadget-config-defaults-to-snaps test
The test fails when either two variants are executed in the same machine or the test execution is reapetead
The problem is that the snap lib ie cleaned but the test-snapd-with-configure and test-snapd-with-default-configure snaps are leaving leftovers in /snap and /var/snap, so during the second execution, the files in SNAP_COMMON are the created in the first one.
The solution is to remove test-snapd-with-default-configure and clean the leftovers for test-snapd-with-configure snap
interfaces/audio: allow to provide pipewire/pulse slots from a containerized pipewire/desktop (#12865)
* UDENG-535: allow access to pipewire socket
This PR ports UDENG-418 to upstream, that enables audio in core Desktop. It allows access to the pipewire socket from snapped applications, and allows to have pipewire running inside a snap container. To avoid security issues, it only allows to access the sockets located at the folder belonging to the snap that owns the slot.
With this patch, audio works fine in Core Desktop, and also screen sharing.
* Replace PLUG_SECURITY_TAGS with SLOT_SECURITY_TAGS
