Unblock the CSIT Dual Stack Failure Issues

Unblock the CSIT Dual Stack Failure Issues

Issue:
======
The following exception was seeing from the karaf
log for dual stack network L3 use case testing
post MRI patch[0] merge

Exception:
Change-Id: I5e07f599c2147e1446659d2df870439dbfbd71a3
------------
2020-06-26T11:11:24,156 | ERROR | jobcoordinator-main-task-9 |
NeutronvpnManager                | 360 -
org.opendaylight.netvirt.neutronvpn-impl - 0.11.0.SNAPSHOT | Future
(eventually) failed: addSubnetToVpn: Failed while creating VPN interface
for vpnId 73d6297b-fe26-4563-a228-496ad11f1178, portId
Uuid{_value=6673c43c-9731-4e17-aef0-c4c8abf42829}a5a9eed3-9d77-4ce0-870e-94adb2b89f15,
subnetId {}
java.lang.IllegalArgumentException: Multiple entries with same key:
AdjacencyKey{_ipAddress=10.0.0.2/32}=Adjacency{_adjacencyType=PrimaryAdjacency,
_ipAddress=10.0.0.2/32, _macAddress=fa:16:3e:97:64:b9,
_subnetId=Uuid{_value=125223dd-be4a-404a-b34a-5fcac0b609d3},
augmentation=[]} and
AdjacencyKey{_ipAddress=10.0.0.2/32}=Adjacency{getAdjacencyType=PrimaryAdjacency,
getIpAddress=10.0.0.2/32, getMacAddress=fa:16:3e:97:64:b9,
getSubnetId=Uuid{_value=125223dd-be4a-404a-b34a-5fcac0b609d3},
isPhysNetworkFunc=false, augmentation=[]}. To index multiple values under
a key, use Multimaps.index.

Solution:
==========
Post MRI patch we have changed the List to Map data store for the
VPN interface adjacency. With this patch we have removed the
duplicate VPN interface adjacency before we add into the DS.

[0] https://git.opendaylight.org/gerrit/c/netvirt/+/89660

JIRA: NETVIRT-1677

Change-Id: I76977dcf5644909540d785cd228644d872570e31
Signed-off-by: Karthikeyan Krishnan <karthikeyangceb007@gmail.com>