fix the issue which timeout is too short for bgp shut #7543

What is the motivation for this PR?
flaky failure for platform test on 2700 platforms

How did you do it?
2 changes:

To extend the timeout from 30 seconds to 60, and increase the delay from 0 to 5 seconds.
To add some debug log
How did you verify/test it?
Run local test.

tests/common/fixtures/duthost_utils.py

@@ -191,9 +191,13 @@ def check_ebgp_routes(num_v4_routes, num_v6_routes, duthost):
     MAX_DIFF = 5
     sumv4, sumv6 = duthost.get_ip_route_summary()
     rtn_val = True
-    if 'ebgp' in sumv4 and 'routes' in sumv4['ebgp'] and abs(int(float(sumv4['ebgp']['routes'])) - int(float(num_v4_routes))) >= MAX_DIFF:
+    if 'ebgp' in sumv4 and 'routes' in sumv4['ebgp'] and \
+            abs(int(float(sumv4['ebgp']['routes'])) - int(float(num_v4_routes))) >= MAX_DIFF:
+        logger.info("IPv4 ebgp routes: {}".format(float(sumv4['ebgp']['routes'])))
         rtn_val = False
-    if 'ebgp' in sumv6 and 'routes' in sumv6['ebgp'] and abs(int(float(sumv6['ebgp']['routes'])) - int(float(num_v6_routes))) >= MAX_DIFF:
+    if 'ebgp' in sumv6 and 'routes' in sumv6['ebgp'] and \
+            abs(int(float(sumv6['ebgp']['routes'])) - int(float(num_v6_routes))) >= MAX_DIFF:
+        logger.info("IPv6 ebgp routes: {}".format(float(sumv6['ebgp']['routes'])))
         rtn_val = False
     return rtn_val
 
@@ -216,7 +220,7 @@ def shutdown_ebgp(duthosts, rand_one_dut_hostname):
         # Shutdown all eBGP neighbors
         duthost.command("sudo config bgp shutdown all")
         # Verify that the total eBGP routes are 0.
-        pytest_assert(wait_until(30, 2, 0, check_ebgp_routes, 0, 0, duthost),
+        pytest_assert(wait_until(60, 2, 5, check_ebgp_routes, 0, 0, duthost),
                       "eBGP routes are not 0 after shutting down all neighbors on {}".format(duthost))
         pytest_assert(wait_until(orch_cpu_timeout, 2, 0, check_orch_cpu_utilization, duthost, orch_cpu_threshold),
                       "Orch CPU utilization {} > orch cpu threshold {} after shutdown all eBGP"