/usr/share/debhelper/autoscripts/postinst-lcd-keymaps is in dh-consoledata 0.7.88.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | if [ "$1" = "configure" ]
then
  # Do nothing if console-common is not installed.
  if [ -x /usr/share/console/getkmapchoice.pl ] 
  then 
      . /usr/share/debconf/confmodule
      # If the entry contains a / it's broken so overwrite it with a default
      # value.  See see #110873
      if db_get console-data/keymap/full && echo "$RET" | grep -q "/"; then
          db_set console-data/keymap/full us
      fi
      echo >&2 "Looking for keymap to install:"
      if /usr/share/console/getkmapchoice.pl
      then
  	install-keymap `PERL_BADLANG=0 \
	   /usr/share/console/getkmapchoice.pl 2>&1 | tail -n 1`
      fi
  fi
fi
 |