Update Kubernetes to 1.18.0

Updates Kubernetes to 1.18.0 and removes patches that are no
longer needed. The directories themselves and the build code that deals
with patching is left intact since rebasing D389 and subsequent K8s work
would otherwise be unnecessarily complicated.

Test Plan: Should be covered by CI

X-Origin-Diff: phab/D470
GitOrigin-RevId: 5c7749926f0adcc8d58e3bff3ce6413bab1d797d
diff --git a/core/cmd/kube-controlplane/BUILD b/core/cmd/kube-controlplane/BUILD
index 6ae215a..cc0427a 100644
--- a/core/cmd/kube-controlplane/BUILD
+++ b/core/cmd/kube-controlplane/BUILD
@@ -27,10 +27,10 @@
         "@kubernetes//cmd/kube-apiserver/app:go_default_library",
         "@kubernetes//cmd/kube-controller-manager/app:go_default_library",
         "@kubernetes//cmd/kube-scheduler/app:go_default_library",
-        "@kubernetes//pkg/client/metrics/prometheus:go_default_library",
-        "@kubernetes//pkg/version/prometheus:go_default_library",
         "@kubernetes//staging/src/k8s.io/component-base/cli/flag:go_default_library",
         "@kubernetes//staging/src/k8s.io/component-base/logs:go_default_library",
+        "@kubernetes//staging/src/k8s.io/component-base/metrics/prometheus/restclient:go_default_library",
+        "@kubernetes//staging/src/k8s.io/component-base/metrics/prometheus/version:go_default_library",
         "@kubernetes//vendor/github.com/spf13/cobra:go_default_library",
         "@kubernetes//vendor/github.com/spf13/pflag:go_default_library",
     ],
diff --git a/core/cmd/kube-controlplane/main.go b/core/cmd/kube-controlplane/main.go
index aad7f04..854e742 100644
--- a/core/cmd/kube-controlplane/main.go
+++ b/core/cmd/kube-controlplane/main.go
@@ -45,11 +45,11 @@
 
 	cliflag "k8s.io/component-base/cli/flag"
 	"k8s.io/component-base/logs"
+	_ "k8s.io/component-base/metrics/prometheus/restclient" // for client metric registration
+	_ "k8s.io/component-base/metrics/prometheus/version"    // for version metric registration
 	kubeapiserver "k8s.io/kubernetes/cmd/kube-apiserver/app"
 	kubecontrollermanager "k8s.io/kubernetes/cmd/kube-controller-manager/app"
 	kubescheduler "k8s.io/kubernetes/cmd/kube-scheduler/app"
-	_ "k8s.io/kubernetes/pkg/client/metrics/prometheus" // for client metric registration
-	_ "k8s.io/kubernetes/pkg/version/prometheus"        // for version metric registration
 )
 
 func main() {