Security-manager 1.1.16 has made this obsolete.
There is no longer a need for manually adding privilege-related supplementary
groups to user sessions. They will be added by a dedicated NSS plugin:
libnss-security-manager.
This reverts commit
78a648a0611caccdd87a38f99f65ba296608da69.
Change-Id: Ic421a2ee65550762356784b585d2fba8645fbd5c
Environment=DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/%i/dbus/user_bus_socket
Environment=XDG_RUNTIME_DIR=/run/user/%i
Capabilities=cap_sys_admin,cap_mac_admin,cap_mac_override,cap_setgid,cap_dac_override=i
-SupplementaryGroups=priv_mediastorage priv_externalstorage priv_message_read priv_mapservice priv_network_get priv_internet
SecureBits=keep-caps
TimeoutStartSec=infinity