/usr/share/dbus-1/services/org.gnome.Epiphany.service is in epiphany-browser-data 3.10.3-0ubuntu2.
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.Epiphany
Exec=/usr/bin/epiphany --headless-mode
|