zebra: bridge flap handle vlan membership update

zebra: bridge flap handle vlan membership update

Upon bridge flap, the associated SVD case,
VLAN membership is not updated correctly.
When SVI comes up, the VNI could not associate
with it as bridge VLAN membership was not updated.

Ticket: #3821632

Testing:

Before fix:
-----------
tor-1:#ifdown br_l3vni ; sleep 1 ; ifup br_l3vni
tor-1:# vtysh -c 'show evpn vni 8888'
VNI: 8888
  Type: L3
  Tenant VRF: sym_1
  Vlan: 490
  Bridge: br_l3vni
  Local Vtep Ip: 27.0.0.9
  Vxlan-Intf: vxlan99
  SVI-If: None    <<<<<< SVI not found
  State: Down     <<<<<< status remained in down BGP is not informed
  VNI Filter: none
  System MAC: None
  Router MAC: None
  L2 VNIs: 1800 1801 1900 1901

After fix:
----------

tor-1:# ifdown br_l3vni; sleep 1; ifup br_l3vni
tor-1:# vtysh

Hello, this is FRRouting (version 8.4.3).
Copyright 1996-2005 Kunihiro Ishiguro, et al.

tor-1# show evpn vni 8888
VNI: 8888
  Type: L3
  Tenant VRF: sym_1
  Vlan: 490
  Bridge: br_l3vni
  Local Vtep Ip: 27.0.0.9
  Vxlan-Intf: vxlan99
  SVI-If: vlan490_l3 <<<<<<
  State: Up          <<<<<<
  VNI Filter: none
  System MAC: 44:38:39:ff:ff:29
  Router MAC: 44:38:39:ff:ff:29
  L2 VNIs: 1800 1801 1900 1901

Signed-off-by: Chirag Shah <chirag@nvidia.com>