Now that admins have a way to specify a runtime_config_path for a
runtime, let's honor this information as pass it down to the
containerd-shim-v2 binary as part of the CreateTask request.

Here you can see what's the current behaviour, without this patch:
```
[fidencio@crio ~]$ kubectl get pods
No resources found in default namespace.

[fidencio@crio ~]$ cat /etc/crio/crio.conf.d/99-runtimes
[crio.runtime.runtimes.kata]
runtime_path = "/usr/local/bin/containerd-shim-kata-v2"
runtime_root = "/run/vc"
runtime_type = "vm"
privileged_without_host_devices = true

[fidencio@crio ~]$ kubectl apply -f ~/simple.yaml
pod/simple created

[fidencio@crio ~]$ kubectl describe pod simple
Name:         simple
Namespace:    default
...
Events:
  Type     Reason                  Age   From               Message
  ----     ------                  ----  ----               -------
  Normal   Scheduled               8s    default-scheduler  Successfully assigned default/simple to crio
  Warning  FailedCreatePodSandBox  8s    kubelet            Failed to create pod sandbox: rpc error: code = Unknown desc = CreateContainer failed: Cannot find usable config file (config file "/etc/kata-containers/configuration.toml" unresolvable: file /etc/kata-containers/configuration.toml does not exist, config file "/usr/share/defaults/kata-containers/configuration.toml" unresolvable: file /usr/share/defaults/kata-containers/configuration.toml does not exist): not found
```

And the changes with this patch applied:
```
[fidencio@crio ~]$ kubectl get pods
No resources found in default namespace.

[fidencio@crio ~]$ cat /etc/crio/crio.conf.d/99-runtimes
[crio.runtime.runtimes.kata]
runtime_path = "/usr/local/bin/containerd-shim-kata-v2"
runtime_root = "/run/vc"
runtime_type = "vm"
privileged_without_host_devices = true
runtime_config_path = "/tmp/config.toml"

[fidencio@crio ~]$ kubectl apply -f ~/simple.yaml
pod/simple created

[fidencio@crio ~]$ kubectl describe pod
Name:         simple
Namespace:    default
...
Events:
  Type    Reason     Age   From               Message
  ----    ------     ----  ----               -------
  Normal  Scheduled  7s    default-scheduler  Successfully assigned default/simple to crio
  Normal  Pulling    6s    kubelet            Pulling image "quay.io/prometheus/busybox:latest"
  Normal  Pulled     4s    kubelet            Successfully pulled image "quay.io/prometheus/busybox:latest" in 1.990972055s
  Normal  Created    3s    kubelet            Created container basic
  Normal  Started    3s    kubelet            Started container basic

[fidencio@crio ~]$ kubectl get pods
NAME     READY   STATUS    RESTARTS   AGE
simple   1/1     Running   0          10s
```

Fixes: cri-o#4591

Signed-off-by: Fabiano Fidêncio <[email protected]>