cri-containerd.test: Add containerd restart test
cri-containerd.test: Add containerd restart test

Adds a test case that runs a pod+container, restarts containerd, then
verifies that the pod+container were terminated. This validates the
change made in the CRI fork [1] to terminate containers when containerd
is restarted.

[1]: https://github.com/kevpar/cri/commit/f8e83e63cc027d0e9c0c984f9db3cba58d3672d4

Signed-off-by: Kevin Parsons <179e5f33d278e7f4e6411489dacfa9a734384f98@microsoft.com>

Microsoft/hcsshim