Fully setup test TUN iface on create.

This CL updates TestNetworkService to fully setup test TUN
interfaces when created. Previously, the interface was only
created in netd when the Test Network was created.

Bug: 182291467
Bug: 189125789
Test: atest Ikev2VpnTest IpSecManagerTunnelTest
Change-Id: I4c1262e566517bbb03dd610f595e4d18bc4e7735
Merged-In: I4c1262e566517bbb03dd610f595e4d18bc4e7735
(cherry picked from commit 615237a818)

service/src/com/android/server/TestNetworkService.java

@@ -48,7 +48,6 @@ import com.android.internal.annotations.GuardedBy;
 import com.android.internal.annotations.VisibleForTesting;
 import com.android.net.module.util.NetdUtils;
 import com.android.net.module.util.NetworkStackConstants;
-import com.android.net.module.util.PermissionUtils;
 
 import java.io.UncheckedIOException;
 import java.net.Inet4Address;
@@ -123,6 +122,8 @@ class TestNetworkService extends ITestNetworkManager.Stub {
                         addr.getPrefixLength());
             }
 
+            NetdUtils.setInterfaceUp(mNetd, iface);
+
             return new TestNetworkInterface(tunIntf, iface);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
@@ -324,14 +325,6 @@ class TestNetworkService extends ITestNetworkManager.Stub {
         }
 
         try {
-            final long token = Binder.clearCallingIdentity();
-            try {
-                PermissionUtils.enforceNetworkStackPermission(mContext);
-                NetdUtils.setInterfaceUp(mNetd, iface);
-            } finally {
-                Binder.restoreCallingIdentity(token);
-            }
-
             // Synchronize all accesses to mTestNetworkTracker to prevent the case where:
             // 1. TestNetworkAgent successfully binds to death of binder
             // 2. Before it is added to the mTestNetworkTracker, binder dies, binderDied() is called