@tizianarefice I agree with @dominichamon comment, and I recommend either a standard config location like /etc/flashpolicy.xml or in the slice's home directory /home/iupui_ndt/.   The first is a little more general, the second is a little simpler in the m-lab package context.

In either case, we need to also ensure that the new files are included in the generated package.

I recommend adding two lines to prepare.sh to include these new files, like this one:
    https://github.com/m-lab-tools/ndt-support/blob/master/init/prepare.sh#L61

In that example, BUILD_DIR is the ultimate SLICEHOME directory, /home/iupui_ndt, once the package is installed.  If you use this as the hardcoded location of the policy file, then you don't need to do anything else.  If you want that file in a different location, say /etc/, then also add a line in https://github.com/m-lab-tools/ndt-support/blob/master/init/initialize.sh to copy the file where it's expected.

To start & stop the script, add a corresponding block like those here:
    https://github.com/m-lab-tools/ndt-support/blob/master/init/start.sh#L28
    https://github.com/m-lab-tools/ndt-support/blob/master/init/stop.sh#L12