floss: telephony: Support for SCO manipulate

A SCO call should be established at the following timings:
- A call become active
- HF is connected while a call is already active

Added the following functions for simulating audio connection transfer:
- AudioConnect (which is actually StartScoCall)
- AudioDisconnect (which is actually StopScoCall)

Bug: 214149380
Tag: #floss
Test: HFP/AG/ACS/*, HFP/AG/ATH/*
Change-Id: I21ee22f3f1834a49409ce378757b315c7ee1031c