Fix "Failed to stop docker.service: Unit docker.service not loaded" log error on start with kvm2 driver and containerd/crio runtimes

[ilya-zuyev]

when minikube is starting we try to disable non-active runtimes , but for kvm2/containerd combination it leads to a log error
E0610 10:36:19.140582 12060 docker.go:159] "Failed to stop" err="sudo systemctl stop -f docker.service: Process exited with status 5\nstdout:\n\nstderr:\nFailed to stop docker.service: Unit docker.service not loaded.\n" service="docker.service"

ilyaz@skeletron --- g/minikube ‹master* ?› » out/minikube start --driver=kvm2 --container-runtime=containerd                                                                                                                                         7 ↵
* minikube v1.21.0-beta.0 on Ubuntu 21.04
* Using the kvm2 driver based on existing profile
* Starting control plane node minikube in cluster minikube
* Restarting existing kvm2 VM for "minikube" ...
E0610 10:36:19.140582   12060 docker.go:159] "Failed to stop" err="sudo systemctl stop -f docker.service: Process exited with status 5\nstdout:\n\nstderr:\nFailed to stop docker.service: Unit docker.service not loaded.\n" service="docker.service"
* Preparing Kubernetes v1.20.7 on containerd 1.4.4 ..
* ```

[afbjorklund]

Docker was normally always started, due to using Docker Machine.