/usr/share/akonadi/firstrun/birthdaycalendar is in kdepim-runtime 4:16.04.2-2+b2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | [Agent]
Id=birthdaycalendar
Type=akonadi_birthdays_resource
|