The ID_MM_PROCESS tag should be set by the user when using the
allowlist filter, we must not ship any device flagged by default with
that tag.
Moreover, the two ENV actions in a single rule is something not
currently supported by the builtin udev rule parser that is used in
systems without udev (e.g. openwrt).
Fixes https://gitlab.freedesktop.org/mobile-broadband/ModemManager/-/issues/779
This will make it slightly easier to port mm_port_serial_at_command() to
use GTask, since we won't have to keep a pointer to the result in GTask
after _finish() has been called.
In most cases the caller needs the value anyway, so this doesn't add too
much hasle.
We are going to allow including the plugin sources built within the
ModemManager daemon binary; moving the sources within the daemon
sources directory makes it easier.