User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0

Steps to reproduce:

Using ESR 78 on Linux with restricted user quota, the size of the storage folder/directory under a user's Firefox profile folder/directory can cause the user to go over quota

The size of the storage directory is by far the largest user of disk space (after the cache directory - that we already relocate to a non-quota'd scratch disk)

There doesn't appear to be a way to limit the size of the storage folder/directory - I believe the limit is based on available disk size, but this doesn't help when user quotas are in use

It would be a good idea to be able to overwrite the calculated size limit with a preference that, when set, can limit the size to something acceptable

Windows has profile quotas as well:

https://getadmx.com/?Category=Windows_10_2016&Policy=Microsoft.Policies.UserProfiles::LimitSize

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.