Aliendalvik does not use /system/etc/hosts, it has its own hosts file inside the read-only system image.
You can use /etc/hosts for android apps by adding the following line to /var/lib/lxc/aliendalvik/extra_config:
lxc.mount.entry = /etc/hosts system/etc/hosts none bind,create=file 0 0
This will “overload” the hosts file inside the read-only system.img with the /etc/hosts from outside the LXC container.
See adblock via /etc/hosts on XA2/AlienDalvik v8 - together.jolla.com