Increase verbosity of Firewall check results

Create dump of iptables rules before running check
and increase verbosity of log message if test fails.
Also do not remove temporary check file, just rename it.

Change-Id: I55fa25e7ef0d2a42899b98600297741ad53d931c
Closes-bug: #1378745
Merge "Increase verbosity of Firewall check results"