Automatic merge from submit-queue (batch tested with PRs 41644, 42020, 41753, 42206, 42212)
Burstable QoS cgroup has cpu shares assigned
**What this PR does / why we need it**:
This PR sets the Burstable QoS cgroup cpu shares value to the sum of the pods cpu requests in that tier. We need it for proper evaluation of CPU shares in the new QoS hierarchy.
**Special notes for your reviewer**:
It builds against the framework proposed for https://github.com/kubernetes/kubernetes/pull/41833