TrustyRpc: Adding a create session with initialization callback function

Original RpcTrustyConnect function didn't allow callbacks on the
connection. Enabling this functionality required us to do some initialization
on the session itself before connecting.
Added a RpcTrustyConnectWithSessionInitializer function that
allows the caller to pass a callback function that can be used to initialize
the session object before a connection is made.
Tested that this change can be used to modify setMaxIncomingThreads to enable
callbacks and one-way functions on it.

Bug: None
Test: None
Change-Id: I9b53b54131a2c7fd24294aae5ab102b7c0f154e2