Fix condition intended to skip iBGP neighbors to work on single-asic (#…

…15411)

Fixes #13662 added support for running bgp/test_bgp_session_flap.py on T2 topology.
However, the condition it added to skip iBGP neighbors only works on multi-asic LCs:
if 'asic' not in v['description'].lower():

The better solution is to check the BGP session's peer group which will indicate if it's internal or not regardless of single-asic or multi-asic

tests/bgp/test_bgp_session_flap.py

@@ -66,7 +66,8 @@ def setup(tbinfo, nbrhosts, duthosts, enum_frontend_dut_hostname, enum_rand_one_
     tor_neighbors = dict()
     neigh_asn = dict()
     for k, v in bgp_facts['bgp_neighbors'].items():
-        if 'asic' not in v['description'].lower():
+        # Skip iBGP neighbors
+        if "INTERNAL" not in v["peer group"] and "VOQ_CHASSIS" not in v["peer group"]:
             neigh_keys.append(v['description'])
             neigh_asn[v['description']] = v['remote AS']
             tor_neighbors[v['description']] = nbrhosts[v['description']]["host"]