This allows to run phosh directly from e.g. gdm which makes testing
on GNOME way easier (and will enable e.g. uploading to Debian since
no systemd unit fiddling is required to try things out).
For desktop use the session's dependency on sm.puri.OSK0 is what
makes thinks harder than necessary.
Signed-off-by: Guido Günther <email@example.com>