ipa_proto: Allow configuring ack initiation behavior

When the osmo-msc version 1.6.1 connects to the osmo-hlr, it sends an
id response and an immediate ack. This commit allows initiating the
handshake with an ack rather than an id request (as is done by ipa
*clients*, like a bts towards a bsc, or the msc towards the hlr) if
needed to mimic behavior of particular components.

Change-Id: I6ab3c9efb51e806f582ce8f473a13ee73ca1567e
2 files changed