Automatic merge from submit-queue (batch tested with PRs 38676, 41765, 42103, 41833, 41702)
kubelet: cm: refactor QoS logic into seperate interface
This commit has no functional change. It refactors the QoS cgroup logic into a new `QOSContainerManager` interface to allow for better isolation for QoS cgroup features coming down the pike.
This is a breakout of the refactoring component of my QoS memory limits PR https://github.com/kubernetes/kubernetes/pull/41149 which will need to be rebased on top of this.
@vishh @derekwaynecarr