racoon: Explicitly request CAP_NET_BIND_SERVICE, CAP_NET_RAW.

'racoon' was not explicitly requesting these capabilities. Add them.
This makes racoon's requested capabilities match its SELinux policy.
With racoon explicitly requesting all its capabilities, we can start
it as user 'vpn'.

Bug: 34744732
Test: 'start racoon', 'cat /proc/`pgrep racoon`/status'.
Test: "Uid" lines show 'vpn' uid (1016).
Test: "Cap" lines show correct mask: 0000000000003400
Change-Id: Ic3823de600a0b7dba9024346e17567e404a01a91