HI,
I don't see any document for the Android based VPN clinet howevever we can try to help you establish this VPN.
1: Do you already have dialup VPNs working using shrewsoft? IKE V1 or IKE V2 ?
2: This document talks about IKEV2 implemantation however the Android client seens to be IKE V1.
If you have configured the IKEv1 on the firewall and android client fails then do you see any log in the "get event" for the failed VPN?
Thanks,
Vikas