kubelet/stats: verify there is at least one process in each container

0 processes is too low a bar to be meaningfully testing that the process
stats are being reported.

Signed-off-by: Peter Hunt <pehunt@redhat.com>

test/e2e_node/summary_test.go

@@ -259,7 +259,7 @@ var _ = SIGDescribe("Summary API", framework.WithNodeConformance(), func() {
 					"InodesUsed":     bounded(0, 1e8),
 				}),
 				"ProcessStats": ptrMatchAllFields(gstruct.Fields{
-					"ProcessCount": bounded(0, 1e8),
+					"ProcessCount": bounded(1, 1e8),
 				}),
 			})