/usr/share/gnome-session/sessions/unity.session

This file is indexed.

/usr/share/gnome-session/sessions/unity.session is in unity-session 3.28.1-0ubuntu2.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

[GNOME Session]
Name=Unity
RequiredComponents=unity-settings-daemon;
DesktopName=Unity:Unity7:ubuntu

unity-session 3.28.1-0ubuntu2 / usr / share / gnome-session / sessions / unity.session