Kubernetes set Eviction Thresholds, system-reserved , kube-reserved
Using kubectl command-line tool to achieve your goal is not feasible, as it only sends commands to api-server and retrieves results without any possibility to change global cluster configuration. The above parameters belong to kubelet configuration. Kubelet is the node agent in a Kubernetes cluster and is responsible for the Pod lifecycle management on each local Node. Representing itself as a service, kubelet interacts with the etcd store in order to read configuration details or write new values.
You can apply specific flags when you implement kubelet service on your node or consider to change the configuration on a live cluster by changing parameters accordingly on the target Node.
There is a separate discussion about customization of kubelet parameters on AKS described here.