[acl] Fix test_stress_acl failed in mx (sonic-net#15144)

What is the motivation for this PR?
MX failed to fetch acl port due to DATAACL table in running config is removed by this PR: sonic-net#11250

How did you do it?
Fetch acl port from mg_facts

How did you verify/test it?
Run test

Author: yaqiangz

tests/acl/test_stress_acl.py

@@ -92,7 +92,7 @@ def prepare_test_file(rand_selected_dut):
 def prepare_test_port(rand_selected_dut, tbinfo):
     mg_facts = rand_selected_dut.get_extended_minigraph_facts(tbinfo)
     if tbinfo["topo"]["type"] == "mx":
-        dut_port = rand_selected_dut.acl_facts()["ansible_facts"]["ansible_acl_facts"]["DATAACL"]["ports"][0]
+        dut_port = mg_facts["minigraph_acls"]["DataAcl"][0]
     else:
         dut_port = list(mg_facts['minigraph_portchannels'].keys())[0]
     if not dut_port: