Hi, SELinux has recently added a new policy module: container. See: https://github.com/SELinuxProject/refpolicy/pull/467. container's policy is adding container engines support. This issue is just to track the integration of this policy into the Gentoo overlay. I would be more than happy to submit a PR as soon as a new release is cut.
This is in the tree now as of 2.20220106-r1 :)