addons: bridge: fix running_vids value when cache is stale

addons: bridge: fix running_vids value when cache is stale

Ticket: CM-12552
Reviewed By: julien, nikhil
Testing Done: tested with failing config with bridge-access 1

This is similar to the fix done in the below commit for pvid:
"5061730ea5bf ("addons: bridge: fix default pvid handling in cases where
cache is stale")"

easier steps to reproduce:
- have a vlan aware bridge with more than one ports
- add 'bridge-access 1' to one of the ports
- boot the box with the config
- check that the  vlans are fine
- ifdown <interface_with_bridge_access_1>
- ifreload -a
- the interface with bridge_access 1 does
not have the pvid flag on vlan 1

This patch makes sure we assume the right running
vid and pvid value ie [1] and 1 if the
cache returns no values. vid = [1] and pvid = 1
are the kernel default/initial values for a port.

Signed-off-by: Roopa Prabhu <roopa@cumulusnetworks.com>