/usr/share/bash-completion/completions/ is in lxc-utils 3.0.0-0ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/bash-completion/completions/lxc-attach
/usr/share/bash-completion/completions/lxc-cgroup
/usr/share/bash-completion/completions/lxc-console
/usr/share/bash-completion/completions/lxc-copy
/usr/share/bash-completion/completions/lxc-create
/usr/share/bash-completion/completions/lxc-destroy
/usr/share/bash-completion/completions/lxc-device
/usr/share/bash-completion/completions/lxc-execute
/usr/share/bash-completion/completions/lxc-freeze
/usr/share/bash-completion/completions/lxc-info
/usr/share/bash-completion/completions/lxc-monitor
/usr/share/bash-completion/completions/lxc-snapshot
/usr/share/bash-completion/completions/lxc-start
/usr/share/bash-completion/completions/lxc-stop
/usr/share/bash-completion/completions/lxc-unfreeze
/usr/share/bash-completion/completions/lxc-utils
/usr/share/bash-completion/completions/lxc-wait