/usr/lib/firefox/ is in firefox-locale-kn 28.0+build2-0ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/firefox-addons/extensions/
/usr/lib/firefox-addons/extensions/langpack-kn@firefox.mozilla.org.xpi
/usr/lib/firefox/distribution/
/usr/lib/firefox/distribution/searchplugins/
/usr/lib/firefox/distribution/searchplugins/locale/
/usr/lib/firefox/distribution/searchplugins/locale/kn/
/usr/lib/firefox/distribution/searchplugins/locale/kn/amazondotcom.xml
/usr/lib/firefox/distribution/searchplugins/locale/kn/bing.xml
/usr/lib/firefox/distribution/searchplugins/locale/kn/duckduckgo.xml
/usr/lib/firefox/distribution/searchplugins/locale/kn/google.xml
/usr/lib/firefox/distribution/searchplugins/locale/kn/kannadastore.xml
/usr/lib/firefox/distribution/searchplugins/locale/kn/wikipedia-kn.xml
/usr/lib/firefox/distribution/searchplugins/locale/kn/yahoo-in.xml