Fix kubernetes behave tests (#2707)

Starting from 1.27 there is containerd process, which also uses k3s binary and being detected by pidof. Therefore we will search for "k3s server" string in the process list instead of just "k3s".

features/environment.py

@@ -595,7 +595,7 @@ class KubernetesController(AbstractExternalDcsController):
                 api_process = 'kube-apiserver'
             elif context.startswith('k3d-'):
                 container = '{0}-server-0'.format(context)
-                api_process = 'k3s'
+                api_process = 'k3s server'
             else:
                 return super(KubernetesController, self)._is_running()
             try: