Add sepolicy for the vpnmanager service.

The system server code that backs VPN APIs such as VpnService and
VpnManager currently lives in ConnectivityService and is accessed
via IConnectivityManager.

In S, ConnectivityService is being moved to the tethering
mainline module, but the VPN code is not. So add an new
service (vpnmanager, IVpnManager, VpnManagerService) to support
these APIs.

Service implementation at http://r.android.com/1572982 . That CL
cannot be in a topic with this one because it will conflict in
master and sc-dev.

Bug: 173331190
Test: builds, boots, "dumpsys vpnmanager" throws no errors
Change-Id: Ic09c93cc454ec959a3beda2b09efa74b8db30c27
3 files changed