Fix ConnectivityServiceTest fail.

NetdService#getInstance() will get null object in
WrappedConnectivityService constructor. Then pass this null
INetd object to PermissionMonitor will case NPE in
PermissionMonitor#sendPackagePermissionsToNetd()

Bug: 128024100
Test: atest FrameworksNetTests
Change-Id: Ia1c80f9600a19c4aaf3f3c1b497b355d96c49c8e
Merged-In: I7f185e731db91c30a9b0f14aefbdbb067942190e
Merged-In: Ic77ef73841266da487401ffd657ef63562b6fc1e
(cherry picked from commit 7d215078)