Update to new cadvisor v0.48.1

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

vendor/github.com/google/cadvisor/metrics/prometheus.go

@@ -377,6 +377,13 @@ func NewPrometheusCollector(i infoProvider, f ContainerLabelsFunc, includedMetri
 				getValues: func(s *info.ContainerStats) metricValues {
 					return metricValues{{value: float64(s.Memory.RSS), timestamp: s.Timestamp}}
 				},
+			}, {
+				name:      "container_memory_kernel_usage",
+				help:      "Size of kernel memory allocated in bytes.",
+				valueType: prometheus.GaugeValue,
+				getValues: func(s *info.ContainerStats) metricValues {
+					return metricValues{{value: float64(s.Memory.KernelUsage), timestamp: s.Timestamp}}
+				},
 			}, {
 				name:      "container_memory_mapped_file",
 				help:      "Size of memory mapped files in bytes.",