Move MultinetworkPolicyTracker to services, where it belongs.

This is necessary so that MultinetworkPolicyTracker can see
DeviceConfig. It will also allow removing reflection from
this file to address a long-standing TODO.

Test: build
Change-Id: I968bf67e0e0189b01515242371599c02bc9e2ca2
diff --git a/service/src/com/android/server/ConnectivityService.java b/service/src/com/android/server/ConnectivityService.java
index eb2674e..1236243 100755
--- a/service/src/com/android/server/ConnectivityService.java
+++ b/service/src/com/android/server/ConnectivityService.java
@@ -205,7 +205,6 @@
 import android.net.resolv.aidl.Nat64PrefixEventParcel;
 import android.net.resolv.aidl.PrivateDnsValidationEventParcel;
 import android.net.shared.PrivateDnsConfig;
-import android.net.util.MultinetworkPolicyTracker;
 import android.net.wifi.WifiInfo;
 import android.os.BatteryStatsManager;
 import android.os.Binder;
@@ -272,6 +271,7 @@
 import com.android.server.connectivity.KeepaliveTracker;
 import com.android.server.connectivity.LingerMonitor;
 import com.android.server.connectivity.MockableSystemProperties;
+import com.android.server.connectivity.MultinetworkPolicyTracker;
 import com.android.server.connectivity.NetworkAgentInfo;
 import com.android.server.connectivity.NetworkDiagnostics;
 import com.android.server.connectivity.NetworkNotificationManager;