Description of problem:

prometheus-adapter becomes inaccessible during rollout.

Since prometheus-adapter is updated every 15 days[1], it will be rolled out every time.
No data can be obtained from prometheus-adapter while performing this rollout.

```
the server is currently unable to handle the request (get pods.metrics.k8s.io)
```

[1] https://github.com/openshift/cluster-kube-apiserver-operator/blob/release-4.8/pkg/operator/certrotationcontroller/certrotationcontroller.go#L131-L133

```
openshift-cluster-machine-approver                 machine-approver-58488dbb64-dlb4f                                        2/2     Running     0          26d
openshift-monitoring                               prometheus-adapter-7c878c4b69-mkhhd                                      1/1     Running     0          11d <== here
openshift-monitoring                               prometheus-adapter-7c878c4b69-rmcdk                                      1/1     Running     0          11d <== here
openshift-monitoring                               prometheus-k8s-0                                                         7/7     Running     8          26d
openshift-monitoring                               prometheus-k8s-1                                                         7/7     Running     8          26d
openshift-monitoring                               prometheus-operator-5f86995d86-dclzv                                     2/2     Running     3          26d
```



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

    OCP 4.8

How reproducible:

    every time


Steps to Reproduce:
1. Try to get data from the prometheus-adapter when the rollout takes place
2.
3.

Actual results:

    Unable to get data temporarily.


Expected results:

    Since we have multiple prometheus-adapter, it is expected that data will get.


Additional info:

    This can be a rollout timing-dependent issue.
    Since the prometheus-adapter does not have any probes(readiness/startup), it is ready before the data is available and we can see such problems during that time.