Have PermissionMonitor arbiter which app can access background networks

This will let ConnectivityService send the right callbacks to the
relevant apps.

Test: manual with apps
      runtest frameworks-net
      cts
      new tests for this functionality
Bug: 67408339

Change-Id: I6f08efd9e73c7e191f833d7f307a3bf4c9e2f0b4

core/java/android/net/ConnectivityManager.java

@@ -1976,13 +1976,6 @@ public class ConnectivityManager {
     /* TODO: These permissions checks don't belong in client-side code. Move them to
      * services.jar, possibly in com.android.server.net. */
 
-    /** {@hide} */
-    public static final boolean checkChangePermission(Context context) {
-        int uid = Binder.getCallingUid();
-        return Settings.checkAndNoteChangeNetworkStateOperation(context, uid, Settings
-                .getPackageNameForUid(context, uid), false /* throwException */);
-    }
-
     /** {@hide} */
     public static final void enforceChangePermission(Context context) {
         int uid = Binder.getCallingUid();