* changes: Stop accessing VPNs in getAllVpnInfo. Clear calling identity in registerNetworkAgent. Allow tests to create TRANSPORT_TEST|TRANSPORT_VPN networks. Move applying underlying caps from Vpn to ConnectivityService.
* changes: Stop accessing VPNs in getAllVpnInfo. Clear calling identity in registerNetworkAgent. Allow tests to create TRANSPORT_TEST|TRANSPORT_VPN networks. Move applying underlying caps from Vpn to ConnectivityService.