Automatic merge from submit-queue (batch tested with PRs 50536, 50809, 50220, 50399, 50176)
Set ExecSync timeout in liveness prober.
Although Dockershim doesn't actually support `ExecSync` timeout (see [here](https://github.com/kubernetes/kubernetes/blob/master/pkg/kubelet/dockershim/exec.go#L137)), we should set the timeout, so that the other runtime which supports the timeout could work properly.
Fixes#50389.
/cc @yujuhong @timstclair @feiskyer