Pass kube-apiserver arguments with gravity cluster

I am using gravity to create a kubernetes cluster. Gravity automatically starts the kube-apiserver. Is it possible to pass extra arguments while starting kubeapi server? I tried adding the following to the cluster manifest but this did not work.

 systemOptions:   
     kube-apiserver:
        # List of additional command line args to provide to kubelet daemon
        args: ["--disable-admission-plugins=AlwaysPullImages"]