audiopolicy: engineconfigurable: align with PFW unix socket convention

This CL aligns the engineconfigurable PFW top file to the convention
adopted within parameter-framework.

Bug: 130284799
Test: make

Change-Id: I146430a1a6618d73273dbfd85b060d9fd04a6f9a
Signed-off-by: François Gaffie <francois.gaffie@renault.com>