Fix drop_packets/test_configurable_drop_counters.py (sonic-net#12500)

Testcases fail in drop_packets/test_configurable_drop_counters.py fail in dualtor-aa because some of the traffic goes to the unselected ToR.

How did you do it?
Similar approach is taken as in sonic-net#11921

How did you verify/test it?
Verified on Arista 7260 and Arista 7050 with both dualtor and dualtor-aa topology.

tests/drop_packets/test_configurable_drop_counters.py

@@ -197,6 +197,7 @@ def test_neighbor_link_down(testbed_params, setup_counters, duthosts, rand_one_d
 
 @pytest.mark.parametrize("drop_reason", ["DIP_LINK_LOCAL"])
 def test_dip_link_local(testbed_params, setup_counters, duthosts, rand_one_dut_hostname,
+                        setup_standby_ports_on_rand_unselected_tor,                             # noqa F811
                         send_dropped_traffic, drop_reason, add_default_route_to_dut, generate_dropped_packet):
     """
     Verifies counters that check for link local dst IP.
@@ -222,6 +223,7 @@ def test_dip_link_local(testbed_params, setup_counters, duthosts, rand_one_dut_h
 
 @pytest.mark.parametrize("drop_reason", ["SIP_LINK_LOCAL"])
 def test_sip_link_local(testbed_params, setup_counters, duthosts, rand_one_dut_hostname,
+                        setup_standby_ports_on_rand_unselected_tor,                             # noqa F811
                         send_dropped_traffic, drop_reason, add_default_route_to_dut, generate_dropped_packet):
     """
     Verifies counters that check for link local src IP.