udev looks for rules in 2 locations /etc/udev/rules.d/ and /lib/udev/rules.d/. system defined rules are supposed to be installed in /lib/udev/rules.d/ and not in etc, however libmtp installs the rules into /etc/udev/rules.d/. Reproducible: Always checked with version 1.0.3-r1
Created attachment 254485 [details] fixed ebuild
thanks, fixed in -r2.