Open-cluster-management-io/ocm: cluster-manager permissions may allow a worker node to obtain service account tokens

A flaw was found in Open Cluster Management (OCM) when a user has access to the worker nodes which contain the cluster-manager or klusterlet deployments. The cluster-manager deployment uses a service account with the same name "cluster-manager" which is bound to a ClusterRole also named "cluster-manager", which includes the permission to create Pod resources. If this deployment runs a pod on an attacker-controlled node, the attacker can obtain the cluster-manager's token and steal any service account token by creating and mounting the target service account to control the whole cluster.