Update generic errors with the new http package codes

All of these errors are now part of the standard HTTP method. Formalize
those into our error types and remove duplication and unclear
separation.

pkg/kubelet/server/server_test.go

@@ -39,7 +39,6 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"k8s.io/api/core/v1"
-	apierrs "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/types"
 	"k8s.io/apimachinery/pkg/util/httpstream"
@@ -1065,7 +1064,7 @@ func TestContainerLogsWithInvalidTail(t *testing.T) {
 		t.Errorf("Got error GETing: %v", err)
 	}
 	defer resp.Body.Close()
-	if resp.StatusCode != apierrs.StatusUnprocessableEntity {
+	if resp.StatusCode != http.StatusUnprocessableEntity {
 		t.Errorf("Unexpected non-error reading container logs: %#v", resp)
 	}
 }