Description of problem:
[Host QoS] - Engine should take care and apply host QoS on all the networks attached to the same interface and sync them. 

Currently vdsm applying this change below engine's legs and engine consider networks as out-of-sync.  BZ - 1302020

For example: 

Steps:
1) Attach network 'net1' without host QoS to NIC via setup networks
2) Attach vlan network 'net2' with some host QoS ls=70, rt=200, ul=200 via setup networks to the same NIC

Result:
1) caps reports now that 'net1' has ls=70
hostQos': {'out': {'ls': {'d': 0, 'm1': 0, 'm2': 70}}}

2) Engine report that 'net1' is out-of-sync with the host, because there is a difference between the DC and the host.

- Once syncing the network through the engine, the change is gone and engine wins, the 'ls' that was configured over 'net1' is gone. 

* Another scenario that engine should take care is: 
- 2 vlan networks and 1 VM network(non-vlan) attached to one NIC, once we will configure the non-vlan network(default one on qos concept) with some host QoS, it will apply the max value on all of the other vlan networks that are attached to the same interface. 

Version-Release number of selected component (if applicable):
4.0.2-0.1.rc.el7ev
vdsm-4.18.6-1.el7ev.x86_64

How reproducible:
100

Steps to Reproduce:
See description above^^ 

Actual results + Expected results:
Engine should take care such scenarios(and not vdsm) and apply some host QoS('ls' i guess) on all the networks on the interface. He should sync them as well, networks shouldn't be considered as out-of-sync for sync scenarios.


Additional info:
See also https://bugzilla.redhat.com/show_bug.cgi?id=1302020