rebase: update kubernetes to v1.20.0

updated kubernetes packages to latest
release.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

vendor/k8s.io/apiserver/pkg/admission/initializer/interfaces.go

@@ -19,6 +19,7 @@ package initializer
 import (
 	"k8s.io/apiserver/pkg/admission"
 	"k8s.io/apiserver/pkg/authorization/authorizer"
+	quota "k8s.io/apiserver/pkg/quota/v1"
 	"k8s.io/client-go/informers"
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/component-base/featuregate"
@@ -42,6 +43,12 @@ type WantsAuthorizer interface {
 	admission.InitializationValidator
 }
 
+// WantsQuotaConfiguration defines a function which sets quota configuration for admission plugins that need it.
+type WantsQuotaConfiguration interface {
+	SetQuotaConfiguration(quota.Configuration)
+	admission.InitializationValidator
+}
+
 // WantsFeatureGate defines a function which passes the featureGates for inspection by an admission plugin.
 // Admission plugins should not hold a reference to the featureGates.  Instead, they should query a particular one
 // and assign it to a simple bool in the admission plugin struct.