Add new kubelet configs (#1972)

Signed-off-by: Artiom Diomin <artiom@kubermatic.com>

Author: kron4eg

sdk/apis/cluster/common/consts.go

@@ -139,6 +139,10 @@ const (
 ContainerLogMaxSizeKubeletConfig = "ContainerLogMaxSize"
 ContainerLogMaxFilesKubeletConfig = "ContainerLogMaxFiles"
 MaxPodsKubeletConfig = "MaxPods"
+ImageGCHighThresholdPercent = "ImageGCHighThresholdPercent"
+ImageGCLowThresholdPercent = "ImageGCLowThresholdPercent"
+ImageMinimumGCAge = "ImageMinimumGCAge"
+ImageMaximumGCAge = "ImageMaximumGCAge"
 )
 
 const (