/lib/udev/rules.d/70-android-tools-fastboot.rules is in android-tools-fastboot 4.2.2+git20130218-3ubuntu23.
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 | # Udev rules for letting the console user access fastboot
# 4e40 grouper
# 4ee0 mako/manta
# 4e30 maguro/toro
ACTION=="add|change", SUBSYSTEM=="usb", \
ATTRS{idVendor}=="18d1", ATTRS{idProduct}=="4e30|4e40|4ee0", \
TAG+="uaccess"
|