/usr/share/dbus-1/services/org.gnome.Contacts.service is in gnome-contacts 3.18.1-1ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | [D-BUS Service]
Name=org.gnome.Contacts
Exec=/usr/bin/gnome-contacts --gapplication-service
|