Draft: samsung-a6lte: force pipewire-media-session instead of wireplumber

It seems that pipewire-media-session somehow multiplexes playback and capture into a single IO operation, while wireplumber tries to do both independently, which breaks the low-quality downstream driver by triggering two incompatible DMA transfers at once. This issue can be reproduced without any sound server running at all, aplay -D sysdefault /dev/urandom & sleep 1; arecord -D sysdefault /dev/null results in a second of clear white noise followed by broken sound, so it's clearly a driver issue, but pipewire-media-session "just works" (except for the fact that it's been removed from Alpine).