Add flag to forbid packet loss during remote ping test

By default ping returns success in case target host responded only
on a part of requests. For some tests this may be not suitable.
This patch adds a flag which will allow to configure
check_remote_connectivity function to fail in case packet loss
differs from 0%.

Change-Id: I28bd5c086c3b47b25725efa73577fcc1cf965141
1 file changed