Automatic merge from submit-queue

Node e2e tests for the CPU Manager. 

**What this PR does / why we need it**:
- Adds node e2e tests for the CPU Manager implementation in https://github.com/kubernetes/kubernetes/pull/49186.

**Special notes for your reviewer**: 
- Previous PR in this series: #51180
- Only `test/e2e_node/cpu_manager_test.go` must be reviewed as a part of this PR (i.e., the last commit). Rest of the comments belong in #51357 and #51180.
- The tests have been on run on `n1-standard-n4` and `n1-standard-n2` instances on GCE. 

To run this node e2e test, use the following command:
```sh
make test-e2e-node TEST_ARGS='--feature-gates=DynamicKubeletConfig=true' FOCUS="CPU Manager" SKIP="" PARALLELISM=1
```

CC @ConnorDoyle @sjenning