Automatic merge from submit-queue (batch tested with PRs 45571, 45657, 45638, 45663, 45622)

rkt: Improve the Garbage Collection

**What this PR does / why we need it**:

This PR improve the garbage collection of files written inside the `/var/lib/kubelet/pods/<pod: id>`

It removes the` finished-<pod: id>` file touched during the `ExecStopPost` of the systemd unit.
It also removes the `/dev/termination-log` file mounted into containers .

The termination-log is used to produce a message from the container and collected by the kubelet when the Pod stops.
Especially for the termination-log, removing theses files will free the associated space used on the filesystem.


**Release note**:

`NONE`