Description of problem: OpenShift currently has a few different methods of health checking etcd.

quorum-guard: As part of maintaining the PDB quorum-guard readinessProbe performs a curl GET to the etcd /health endpoint. If the health check fails the container does not report ready status and PDB reporting will reflect one unavailable. This runs every 5s and reporting of failures can be seen in the kubelet logs and also reflected in the etcd logs.

```
2021-05-07 18:18:48.401026 I | etcdserver/api/etcdhttp: /health OK (status code 200)
2021-05-07 18:18:53.498054 I | etcdserver/api/etcdhttp: /health OK (status code 200)
2021-05-07 18:18:58.414041 I | etcdserver/api/etcdhttp: /health OK (status code 200)
2021-05-07 18:19:03.403105 I | etcdserver/api/etcdhttp: /health OK (status code 200)
2021-05-07 18:19:08.407647 I | etcdserver/api/etcdhttp: /health OK (status code 200)
2021-05-07 18:19:13.398697 I | etcdserver/api/etcdhttp: /health OK (status code 200)
```

cluster-etcd-operator health checks: These checks performed by the cluster member controller and will report the health status of etcd members. The controller is set to sync every minute. health check failures are evented and will result in degraded status if a member is unhealthy. 

livenessProbe: etcd uses a liveness probe to perform health checks every 5s. Failures will affect Ready status of the etcd container.

With all of the above, there is no simple reportable what to ensure availability at any given point. For example, etcd-1 has been down for 25s.


Version-Release number of selected component (if applicable):


How reproducible: 100%


Steps to Reproduce:
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Actual results: multiple health checks exist but granularity is not at 1s level and reporting is not reasonably consumable.


Expected results: etcd should report service availability on a 1s granularity to the cluster. The results of these checks should be easily consumable by automation and included in the e2e-intervals report. This data is critical so that we can with certainty explain complex outages between the apiserver and etcd.


Additional info: