Merge pull request #53956 from m1093782566/proxy-metrics

Automatic merge from submit-queue (batch tested with PRs 52479, 53956). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Register sync proxy rules latency metrics in app level

**What this PR does / why we need it**:

IMO, should may should register proxy metrics in app level instead of in specific proxy mode, e.g. iptables, ipvs, winkernel...

By registering sync proxy rules latency metrics in app level, we can reuse codes among different proxiers.

**Which issue this PR fixes**: 

closes #53957

**Special notes for your reviewer**:

@wojtek-t What do you think about it?

**Release note**:

```release-note
NONE
```

cmd/kube-proxy/app/BUILD

@@ -36,6 +36,7 @@ go_library(
         "//pkg/proxy/healthcheck:go_default_library",
         "//pkg/proxy/iptables:go_default_library",
         "//pkg/proxy/ipvs:go_default_library",
+        "//pkg/proxy/metrics:go_default_library",
         "//pkg/proxy/userspace:go_default_library",
         "//pkg/util/configz:go_default_library",
         "//pkg/util/dbus:go_default_library",

cmd/kube-proxy/app/server_others.go

@@ -39,6 +39,7 @@ import (
 	"k8s.io/kubernetes/pkg/proxy/healthcheck"
 	"k8s.io/kubernetes/pkg/proxy/iptables"
 	"k8s.io/kubernetes/pkg/proxy/ipvs"
+	"k8s.io/kubernetes/pkg/proxy/metrics"
 	"k8s.io/kubernetes/pkg/proxy/userspace"
 	"k8s.io/kubernetes/pkg/util/configz"
 	utildbus "k8s.io/kubernetes/pkg/util/dbus"
@@ -143,7 +144,7 @@ func NewProxyServer(config *componentconfig.KubeProxyConfiguration, cleanupAndEx
 		if err != nil {
 			return nil, fmt.Errorf("unable to create proxier: %v", err)
 		}
-		iptables.RegisterMetrics()
+		metrics.RegisterMetrics()
 		proxier = proxierIPTables
 		serviceEventHandler = proxierIPTables
 		endpointsEventHandler = proxierIPTables
@@ -175,6 +176,7 @@ func NewProxyServer(config *componentconfig.KubeProxyConfiguration, cleanupAndEx
 		if err != nil {
 			return nil, fmt.Errorf("unable to create proxier: %v", err)
 		}
+		metrics.RegisterMetrics()
 		proxier = proxierIPVS
 		serviceEventHandler = proxierIPVS
 		endpointsEventHandler = proxierIPVS