[config] config reload needs to handle exceptions while stopping sonic.target

The below error is seen when a 'config reload' operation is performed
while the sonic.target is starting during system startup or a prior config
reload command.

Job for sonic.target canceled.

This error can be ignored if we can try to stop all the services associated
with sonic.target individually. Any processes which did not stop, will be
restarted as part of the "systemctl restart sonic.target" command.

Author: rajendra-dendukuri

config/main.py

@@ -663,6 +663,17 @@ def _get_disabled_services_list(config_db):
 
     return disabled_services_list
 
+def _stop_all_services():
+    # stop all other services
+    for s in _get_sonic_services():
+        try:
+            clicommon.run_command("sudo systemctl stop {}".format(s))
+        except:
+            click.echo("Error encountered while stopping service {}. Continuing..".format(s))
+    try:
+        clicommon.run_command("sudo systemctl stop swss")
+    except:
+        click.echo("Error encountered while stopping swss.service. Continuing..")
 
 def _stop_services():
     try:
@@ -673,8 +684,11 @@ def _stop_services():
         pass
 
     click.echo("Stopping SONiC target ...")
-    clicommon.run_command("sudo systemctl stop sonic.target")
-
+    try:
+        clicommon.run_command("sudo systemctl stop sonic.target")
+    except:
+        click.echo("Failed to stop sonic.target. Stopping all services individually.")
+        _stop_all_services()
 
 def _get_sonic_services():
     out = clicommon.run_command("systemctl list-dependencies --plain sonic.target | sed '1d'", return_cmd=True)