Remove UdpEncapsulationSocket references in VPNs

This changes the IkeSessionParams generation to set a specific Network,
and no longer passes a UDP encapsulation socket.

Bug: 149356682
Test: FrameworksNetTests passing.
Change-Id: I69f184762490b1dd3d3261d00c81fd32bbebddfc
Merged-In: I69f184762490b1dd3d3261d00c81fd32bbebddfc
2 files changed