Lots of checks and features were added to ipsec-tools 0.8.0.
However, they broke the compatibility with existing VPN servers.
I was unable to fix all of them in 0.8.0, so I chose to port
0.7.3 back with the new VPN types we added in ICS release.

Bug: 6191668
Change-Id: I86a7218f7f5146d4a9b129d46c89839a82b0008f