[ACS44] cherry-pick request

[Murali Reddy]

Daan, 

Please cherry-pick below commits in 4.4-forward into 4.4

commit be937a08213f06a801cf07d19867d48dad35d19f
CLOUDSTACK-6832: [OVS]vnet is not released even the network is deleted
    
    fix ensures allocated VNET is released during network shutdown

commit 9dfbdb5ffd2f0981651bc98f1c5d71718a24a29f
CLOUDSTACK-6749: [OVS] xe network-param-get with
    param-key=is-ovs-vpc-distributed-vr-network alway returns error
    
    fixing unnecessary errors in the logs


Thanks.