Add filtering for IPsec algorithms in IKEv2 VPNs

This commit adds support for validating and filtering IPsec algorithms.
Without a public API exposing IKEv2 algorithms (and their respective
public APIs), the allowedAlgorithms can only filter the proposals for
IPsec (Child) SA algorithms.

Additionally, this removes the HMAC_SHA1 from the IKE SA's integrity
algorithm proposals due to insecurity

Bug: 153701879
Test: FrameworksNetTests passing, new tests added
Change-Id: I7e61a1612692db275b751330af5bacbf86836a8c