[database][serializers] Make DatabaseSerializer's description a CharField

Now that the underlying file is read in the
appropriate mode, make it a CharField as the
property of the same name will be called to
fill it.
1 job for text_file_reading in 15 minutes and 15 seconds (queued for 4 seconds)
Status Job ID Name Coverage
  Build
passed #208549
docker-build
build_linux_36

00:15:15

65.0%