Add initial audio configuration for the phone
Note that the pulse/daemon.conf.d/95-librem5.conf specifies
default-script-file = /etc/pulse/librem5.pa
and in librem5-devkit-base, there is a similar /etc/pulse/daemon.conf.d/90-librem5-devkit.conf which specifies
default-script-file = /etc/pulse/librem5-devkit.pa
The new librem5.pa supercedes the librem5-devkit.pa and we rely on the PulseAudio daemon's ordering of configuration snippets. From pulse-daemon.conf(5):
"The files under daemon.conf.d are processed in alphabetical order. In case the same option is set in multiple files, the last file to set an option overrides earlier files."