/usr/share/dbus-1/services/org.kde.activitymanager.service is in kactivitymanagerd 5.12.4-0ubuntu1.
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.kde.ActivityManager
Exec=/usr/bin/kactivitymanagerd
|