chore: split kuttl test steps

[realshuting]

This PR attempts to fix the flaky kuttl test refresh-volumes-in-pods, ref kyverno/kyverno#8334.

I'm able to consistently reproduce the issue by removing the sleep 5 command, the tests ran in Kyverno CIs could take longer than 5s. I'm splitting the check step into 2 and adding more delay to see if it helps.

        ]
    logger.go:42: 16:43:29 | refresh-volumes-in-pods/4-check | running command: [sh -c val=$(kubectl exec pod01 -n refresh-vols-ns -- cat /mnt/foo/foo)
        if [ "$val" = "bar" ]; then exit 0; else exit 1; fi
        ]
    logger.go:42: 16:43:29 | refresh-volumes-in-pods/4-check | command failure, skipping 3 additional commands
    case.go:367: failed in step 4-check
    case.go:369: exit status 1