Fix portmgr write partial port config to app DB issue. (sonic-net#3304)

Fix portmgr write partial port config to app DB issue.

Why I did it
Test case test_add_remove_neg_admin_status unstable.

cfgmgr/portmgr.cpp

@@ -192,6 +192,15 @@ void PortMgr::doTask(Consumer &consumer)
                 }
             }
 
+            if (!portOk)
+            {
+                // Port configuration is handled by the orchagent. If the configuration is written to the APP DB using
+                // multiple Redis write commands, the orchagent may receive a partial configuration and create a port
+                // with incorrect settings.
+                field_values.emplace_back("mtu", mtu);
+                field_values.emplace_back("admin_status", admin_status);
+            }
+
             if (field_values.size())
             {
                 writeConfigToAppDb(alias, field_values);
@@ -201,8 +210,6 @@ void PortMgr::doTask(Consumer &consumer)
             {
                 SWSS_LOG_INFO("Port %s is not ready, pending...", alias.c_str());
 
-                writeConfigToAppDb(alias, "mtu", mtu);
-                writeConfigToAppDb(alias, "admin_status", admin_status);
                 /* Retry setting these params after the netdev is created */
                 field_values.clear();
                 field_values.emplace_back("mtu", mtu);