Add template listener for getting OEM netd

It is a template OemNetdListener that OEM could extend their
binder interface based on it.

Bug: 120251561
Test: built, flashed, booted
        system/netd/tests/runtests.sh pass

Change-Id: Ida29af3f970f65fafc733617ac091747fe10eb11
diff --git a/server/NetdNativeService.cpp b/server/NetdNativeService.cpp
index ab64973..fe575df 100644
--- a/server/NetdNativeService.cpp
+++ b/server/NetdNativeService.cpp
@@ -42,6 +42,7 @@
 #include "NetdConstants.h"  // SHA256_SIZE
 #include "NetdNativeService.h"
 #include "NetdPermissions.h"
+#include "OemNetdListener.h"
 #include "Permission.h"
 #include "Process.h"
 #include "RouteController.h"
@@ -1256,7 +1257,8 @@
 
 binder::Status NetdNativeService::getOemNetd(android::sp<android::IBinder>* listener) {
     ENFORCE_NETWORK_STACK_PERMISSIONS();
-    *listener = nullptr;
+    *listener = com::android::internal::net::OemNetdListener::getListener();
+
     return binder::Status::ok();
 }