/usr/share/cups/ppd-updaters/printer-driver-cups-pdf.ppd-updater is in printer-driver-cups-pdf 2.6.1-21.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 | DRIVER_REGEXP='^lsb/usr/cups-pdf/'
GENNICKNAME_REGEXP=
|