The last release (version 33.0.3p1 [0], added in 28609af5c7) started to
include avbtool and mkdtboimg [1].
This is just a minor fixup to update the package description and stop
installing avbtool twice:
$ sha256sum /nix/store/f2ld3hjbxnafi3jw299nq4mc94xpcmx6-android-tools-33.0.3p1/bin/avbtool*
d4357c43798d6aa6d5cea3b8f3ad39e54244a1105db8048dc673c44119835e1c /nix/store/f2ld3hjbxnafi3jw299nq4mc94xpcmx6-android-tools-33.0.3p1/bin/avbtool
d4357c43798d6aa6d5cea3b8f3ad39e54244a1105db8048dc673c44119835e1c /nix/store/f2ld3hjbxnafi3jw299nq4mc94xpcmx6-android-tools-33.0.3p1/bin/avbtool.py
[0]: https://github.com/nmeum/android-tools/releases/tag/33.0.3p1
[1]: 0652cba5f4