Remove default cni flags from the documentation

cmd/minikube/cmd/config/validations.go

@@ -142,7 +142,7 @@ minikube stop
 
 and then start minikube again with the following flags:
 
-minikube start --container-runtime=containerd  --docker-opt containerd=/var/run/containerd/containerd.sock --network-plugin=cni`)
+minikube start --container-runtime=containerd --docker-opt containerd=/var/run/containerd/containerd.sock`)
 	}
 
 	return nil

deploy/addons/gvisor/README.md

@@ -7,8 +7,7 @@ When starting minikube, specify the following flags, along with any additional d
 
 ```shell
 $ minikube start --container-runtime=containerd  \
-    --docker-opt containerd=/var/run/containerd/containerd.sock \
-    --network-plugin=cni --enable-default-cni
+    --docker-opt containerd=/var/run/containerd/containerd.sock
 ```
 
 ### Enabling gVisor

docs/contributors/minikube_iso.md

@@ -39,8 +39,6 @@ The bootable ISO image will be available in `out/minikube.iso`.
 ```shell
 $ ./out/minikube start \
     --container-runtime=rkt \
-    --network-plugin=cni \
-    --enable-default-cni \
     --iso-url=file://$GOPATH/src/k8s.io/minikube/out/minikube.iso
 ```