community/pipewire: kill previous instance before launch
Patchset from Pranjal Kole pranjal.kole7@gmail.com via aports #3966:
/usr/bin/pipewire was not being killed previously.
The order in which the processes are killed has been
changed to avoid this error message from pipewire-media-session:
[W][77952.698669] ms.core | [ media-session.c: 2211 core_error()] error id:0 seq:799 res:-32 (Broken pipe): connection error
Additionally, pipewire-pulse is now started with the /usr/bin/ prefix,
since a user may have another binary named pipewire in their $PATH.