During the installation of Linux Mint the media codecs shouldn't be installed until later steps

[piotrp02]

When you choose to install media codecs but then for whatever reason you decide not to continue with the installation you get locked out of booting to Linux Mint on the PC. The issue as well as the workaround is described here: https://forums.linuxmint.com/viewtopic.php?t=412942. I think it would be good to install the media codecs alongside the rest of the installation as to avoid this potential issue and not to discourage new users