fonts-freefont-udeb software package provides Freefont Sans fonts for the graphical installer, you can install in your Ubuntu 16.04 LTS (Xenial Xerus) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install fonts-freefont-udeb
fonts-freefont-udeb is installed in your system.
Make ensure the fonts-freefont-udeb package were installed using the commands given below,
$ sudo dpkg-query -l | grep fonts-freefont-udeb *
You will get with fonts-freefont-udeb package name, version, architecture and description in a table
| Distro | Ubuntu 16 04 lts xenial xerus |
| Section | debian-installer udeb packages |
| Package | fonts-freefont-udeb |
| Version | 20120503-4 |
| Description | Freefont Sans fonts for the graphical installer |
| Sub Section | Debian-installer |