[SDK] change scheduler param to realtime when possible in the example.

[thomasfla]

Right now, only the nice value is set in the example. To avoid the user to launch the example with chrt commands, we can add this directly in the code via a system call.
For example in python this works:

import os
os.sched_setscheduler(0,os.SCHED_FIFO,os.sched_param(99))