Support for custom annotations for EtcdCluster pods

[jsloyer]

etcd-operator/pkg/util/k8sutil/k8sutil.go

Lines 83 to 85 in b2a63ce

	func SetEtcdVersion(pod *v1.Pod, version string) {
	pod.Annotations[etcdVersionAnnotationKey] = version
	}

it looks like the annotations that get applied to EtcdCluster pods can not be changed. I was hoping to see if the operator supports custom annotations for the EtcdCluster pods. My use is being able to turn off mTLS for the EtcdCluster pods in a namespace.

If this is not supported any ideas on other ways to add annotations to the EtcdCluster pods or are you open to take a PR to add custom annotations to the EtcdCluster pods?