为webhooks增加setter getter接口 (#192)

* setter and getter for AdmissionWebhook

* fix: compatible if PodAvailableConditionsAnnotation already exist

pkg/webhook/server/generic/pod/pod_webhook.go

@@ -41,3 +41,11 @@ func init() {
 	webhooks = append(webhooks, opslifecycle.New())
 	webhooks = append(webhooks, gracedelete.New())
 }
+
+func RegisterAdmissionWebhook(webhook AdmissionWebhook) {
+	webhooks = append(webhooks, webhook)
+}
+
+func ListAdmissionWebhooks() []AdmissionWebhook {
+	return webhooks
+}