Switch to proper networkcallback api

This will listen properly for the connection of the VPNs.  It will
also listen for disconnects, but may catch them slightly delayed
as the connection may be held on to.

Bug: 16153201
Bug: 17164598
Change-Id: I0c522f7fb4007c3376153c4b2a0345391e0b724f
1 file changed