/usr/lib/firefox/ is in firefox-locale-te 11.0+build1-0ubuntu4.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/firefox-addons/extensions/
/usr/lib/firefox-addons/extensions/langpack-te@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/te/
/usr/lib/firefox/distribution/searchplugins/locale/te/amazondotcom.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/creativecommons.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/eBay-in.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/google.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/wikipedia-te.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/wiktionary-te.xml
/usr/lib/firefox/distribution/searchplugins/locale/te/yahoo-in.xml