[HOW] Turn on Policy-Based IPSec in Fortigate in FortiOS 5

For FortiOS 5 and newer version:  (Policy-Based IPSec is disable)
There is no subtype under VPN policy type.

How to turn on Policy-Based IPsec

Go to System -> Config -> Features, turn on Policy-Based IPSec VPN and click Apply

Then under policy, policy subtype will be enable when VPN policy type is selected.