Sanity/machine-hardening: fix sos reports generation
    
    Fixed sos reports generation, we used incorrect timestamp which was generated
    after hardening and reboot, now the test uses the timestamp generated before
    the hardening and loads it from filesystem after reboot.
    
    There is also optimization when downloading and unselecting rules, we do it
    only once now at the beginning of the test and store the updated datastream
    on filesystem.