Attempt permission fix for Clam AV Logs Directory

[dj-maisy]

What?

We are encountering some permission errors in the Freshclam jobs:

ERROR: Problem with internal logger (UpdateLogFile = /var/log/clamav/freshclam.log).
ERROR: initialize: libfreshclam init failed.
ERROR: Initialization error!
ERROR: Can't open /var/log/clamav/freshclam.log in append mode (check permissions!).

These permission errors are related to the /var/log/clamav directory. In Cisco's Debian Dockerfile, they do this:

install -d -m 755 -g "clamav" -o "clamav" "/var/log/clamav" && \

So let's do something similar for ours, except use the app user and group.

[sengi]

Hm. If it's trying to write logs to the filesystem then that suggests we've missed some config somewhere. All the logs need to go to stderr/stdout otherwise they won't be collected and they'll just fill up the storage they're being written to.