Fix for cooldown time in health checker plugin

[abansal4032]

Use InactiveExitTimestamp instead of ActiveEnterTimestamp for cooldown period in health check monitor.
With ActiveEnterTimestamp we encountered a race condition:
The docker service was configured with RestartSec=10 which coincides with invocation interval of health checker in NPD. The systemd restart of the service and the health check got in sync and the service was killed every 10 sec. The cooldown period did not work since the service never attained Active state even though the systemd start was attempted.
Using InactiveExitTimestamp will help identifying the restart attempt from systemd even before the service attains Active state.

[k8s-ci-robot]

Hi @abansal4032. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[Random-Liu]

/lgtm
/approve

[Random-Liu]

/ok-to-test

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: abansal4032, Random-Liu

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [Random-Liu]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment