Use NetdUtils instead of NetworkManagementService in IpSecService

NetdUtils has the same method(e.g. setInterfaceUp) as
NetworkManagementService so using the one inside NetdUtils instead
and try to remove NetworkManagementService from IpSecService in
the following commit.

Bug: 170598012
Test: atest FrameworksNetTests
Change-Id: I0ed8b0c678b067a655b51b938b6b40eadd985321
diff --git a/services/core/java/com/android/server/IpSecService.java b/services/core/java/com/android/server/IpSecService.java
index f648c3e..b35091b 100644
--- a/services/core/java/com/android/server/IpSecService.java
+++ b/services/core/java/com/android/server/IpSecService.java
@@ -62,6 +62,7 @@
 import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.internal.util.Preconditions;
+import com.android.net.module.util.NetdUtils;
 
 import libcore.io.IoUtils;
 
@@ -1317,7 +1318,7 @@
             netd.ipSecAddTunnelInterface(intfName, localAddr, remoteAddr, ikey, okey, resourceId);
 
             Binder.withCleanCallingIdentity(() -> {
-                mNetworkManager.setInterfaceUp(intfName);
+                NetdUtils.setInterfaceUp(netd, intfName);
             });
 
             for (int selAddrFamily : ADDRESS_FAMILIES) {