audiopolicy: engineconfigurable: Update tool scripts to python 3

As python 2 is beeing deprecated, this CL updates all the tool
scripts to python3.
It also fix some issues revealed by pylint.

Test: lunch audio_configurable target & build
Change-Id: I69a201190c688be3825cbdaa238046367a5d09c7
Signed-off-by: Francois Gaffie <francois.gaffie@renault.com>