deflake TestRestartMonitor
deflake TestRestartMonitor

Fix #5146

Signed-off-by: Akihiro Suda <10ddef0dea2a66ab193b07198faa879adcb213d8@hco.ntt.co.jp>

vdemeester/containerd,dmcgowan/containerd,thaJeztah/containerd,dmcgowan/containerd,estesp/containerd,containerd/containerd,containerd/containerd,estesp/containerd,mikebrow/containerd,thaJeztah/containerd,vdemeester/containerd,mikebrow/containerd