Use windows netsh command to verify interface
addresses and netmasks net package returns.

The test is to be enabled once issue #12811
is fixed.

Updates #12811

Change-Id: I191e350a1403e5133791d4ec59561fefa24f5c61
Reviewed-on: https://go-review.googlesource.com/17478Reviewed-by: Mikio Hara <mikioh.mikioh@gmail.com>
Run-TryBot: Mikio Hara <mikioh.mikioh@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>