After recent conversion of log leafNodes to valueless, a typical firewall rule entry that enables log looks like so:
set firewall ipv4 forward filter rule 101 log
However, the chain level defaults log looks like so (with redundant enable prefix):
set firewall ipv4 forward filter enable-default-log
We can rename enable-default-log for consistency with rule-level entries like so:
set firewall ipv4 forward filter default-log