Comment 1 for bug 1634199

Sounds like the path changed.

You'll need to add the following rule to /etc/apparmor.d/usr.sbin.dnsmasq (or to the local/ include):
  /var/lib/lxd/networks/lxdbr*/dnsmasq.leases rw,

BTW: Do you know if lxd supports different network interface types that don't match the lxdbr* name pattern? If yes, we'll need to add a more permissive rule.