Extend SNMP container cleanup check time allowance (#20985)

At the end of the snmp/test_snmp_link_local.py test, the test will run a
config_reload to clean up the test, then check that the snmp container
is up and running before ending the test.

Currently, the test gives 60s for the snmp container to come back up
after config_reload. This is sufficient for small topos but nowhere
enough for large topos such as qspf t0-d32u32s2.

Extending the allowed wait time to 300s.

Test no longer fails on bad snmp container state on qspf t0-d32u32s2.

Author: justin-wong-ce

tests/snmp/test_snmp_link_local.py

@@ -27,7 +27,7 @@ def check_snmp_lldp_ready():
             wait=True)['ansible_facts']
         return "No Such Instance currently exists" not in str(snmp_facts['snmp_lldp'])
 
-    if not wait_until(60, 5, 0, check_snmp_lldp_ready):
+    if not wait_until(300, 5, 0, check_snmp_lldp_ready):
         pytest.fail("SNMP LLDP not ready for next test")