Make all ModemManager actions available to the purism user

debian/install

 default/09_librem5.gschema.override  usr/share/glib-2.0/schemas/
 default/blackboard-1920.jpg          usr/share/librem5/default-theme/
+/default/org.freedesktop.ModemManager1.pkla /var/lib/polkit-1/localauthority/10-vendor.d/

default/org.freedesktop.ModemManager1.pkla

+[ModemManager Permissions]
+Identity=unix-group:purism
+Action=org.freedesktop.ModemManager1.*
+ResultAny=no
+# We want no here but need to fix
+# https://source.puri.sm/Librem5/phosh/issues/34
+# first
+ResultInactive=yes
+ResultActive=yes