This is in response to logs from a customer that show that we're unable
to run netsh due to the following error:
router: firewall: adding Tailscale-Process rule to allow UDP for "C:\\Program Files\\Tailscale\\tailscaled.exe" ...
router: firewall: error adding Tailscale-Process rule: exec: "netsh": cannot run executable found relative to current directory:
There's approximately no reason to ever dynamically look up the path of
a system utility like netsh.exe, so instead let's first look for it
in the System32 directory and only if that fails fall back to the
previous behaviour.
Updates #10804
Signed-off-by: Andrew Dunham <andrew@du.nham.ca>
Change-Id: I68cfeb4cab091c79ccff3187d35f50359a690573