NIC Offloading modes not applied during network-check

[Michael Polenchuk]

Detailed bug description:
 Some ethernet drivers have offloading mode defaults that need tweaking in order for VLAN traffic to pass as expected. For example:
  driver: amx_xgbe (aarch64 hardware);
  offloading modes (only relevant):
    rx-vlan-filter (defaults to ON, discarding VLAN tags, we want that to be OFF).

Expected results:
 Offloading modes for target NICs are only applied during provisioning/deploying.

Actual result:
 Offloading modes ain't applied during network-check.

Workaround:
 * Skip running netcheck, or expect the VLAN traffic to NOT pass; since offloading modes are not applied during that test;
 * Apply offloading modes by hand for bootstrapped nodes (e.g. from Fuel Master, issue `ssh root@node-X ethtool ethN -K rx-vlan-filter off` (for each inteface affected on each node).

Impact:
 By running the network check after properly configuring offloading modes, one may think the network settings are wrong when the network check fails, although that is a false report, as deploy would work just fine.

Description of the environment:
 Fuel 9.0+

[Michael Polenchuk (mpolenchuk)]

fixed by https://blueprints.launchpad.net/fuel/+spec/graph-concept-extension