/etc/fonts/conf.d/90-ttf-bengali-fonts.conf is in ttf-indic-fonts-core 1:0.5.14ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /etc/fonts/conf.d/../conf.avail/90-ttf-bengali-fonts.conf
/etc/fonts/conf.d/../conf.avail/90-ttf-bengali-fonts.conf