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
(cherry picked from commit 82e1c6e502f5094bf1ff91dc8f5dd4e7c5aab094)
Merge "Increase verbosity of Firewall check results" into stable/5.1