involved_object_name is a label with high cardinality

[njlkj]

kubernetesWarningEventCounterVec = prometheus.NewCounterVec(prometheus.CounterOpts{
	Name: "heptio_eventrouter_warnings_total",
	Help: "Total number of warning events in the kubernetes cluster",
}, []string{
	"involved_object_kind",
	"involved_object_name",
	"involved_object_namespace",
	"reason",
	"source",
})