NSX: fix intermetting UT failure on vshield test_router_create

Logstash shows this happened twice during the past 24 hours.
Let's be proactive and see if we can mitigate the random failure
by raising the poll time.

Change-Id: Icef7de4d9fbb3da037337c607fd7642cc15e0257
Closes-bug: 1292506
Fix KeyError except on router_info in FW Agent

The workflow of creating a firewall when a router without any i/f is present in that tenant
causes a KeyError on the FWAgent. The issue occurs as such routers are present in the list of
routers returned by get_routers() but are not populated in the router_info dict. Adding a check
before accessing the dict to prevent the exception. When an i/f is added to such routers -
_router_added processing in the l3agent will populate the router_info dict and the FWAgent
also picks this up in that context.

Change-Id: I5ea22e88a46e62372a0462e9cb958a08dd9f4c7d
Closes-Bug: #1289643
Merge "NSX: fix intermetting UT failure on vshield test_router_create"
Merge "Fix KeyError except on router_info in FW Agent"