[agent] Add support for histograms with control plane metrics

[atoulme]

Description:
Add support for histograms with control plane metrics behind a feature gate.

[jvoravong]

We also probably have to tackle updating the not-openshift rules for the receivers to values like these. This way we include rules for older and current labels of control plane pods, testing might be blocked if the new labels are not added.

       rule: type == "pod" && (labels["k8s-app"] == "kube-dns" ||  || (labels["tier"] == "control-plane" && labels["component"] == "kube-dns"))
       rule: type == "pod" && (labels["k8s-app"] == "etcd-manager-events" || labels["k8s-app"] == "etcd-manager-main" || (labels["tier"] == "control-plane" && labels["component"] == "etcd"))
       rule: type == "pod" && (labels["k8s-app"] == "kube-controller-manager" || (labels["tier"] == "control-plane" && labels["component"] == "kube-controller-manager"))
       rule: type == "port" && port == 443 && (labels["k8s-app"] == "kube-apiserver" || (labels["tier"] == "control-plane" && labels["component"] == "kube-apiserver"))
       rule: type == "pod" && (labels["k8s-app"] == "kube-proxy" || (labels["tier"] == "control-plane" && labels["component"] == "kube-proxy"))
       rule: type == "pod" && (labels["k8s-app"] == "kube-scheduler" || (labels["tier"] == "control-plane" && labels["component"] == "kube-scheduler"))

[jvoravong]

LGTM since these changes are behind a feature gate. You might still need to pull latest changes from main.