Fix to not miss the entire set of counters to be added in addObject for CounterContext::updateSupportedCount (sonic-net#1493)

* Add a flag dont_clear_support_counter to support a case of not clearing the existing m_supportedCounters
* Use always_check_supported_counters and dont_clear_support_counter for MACSEC_SA

Author: judyjoseph

syncd/FlexCounter.cpp

@@ -865,7 +865,7 @@ class CounterContext : public BaseCounterContext
             return;
         }
 
-        if (always_check_supported_counters)
+        if (always_check_supported_counters && !dont_clear_support_counter)
         {
             m_supportedCounters.clear();
         }
@@ -1663,7 +1663,9 @@ std::shared_ptr<BaseCounterContext> FlexCounter::createCounterContext(
     else if (context_name == COUNTER_TYPE_MACSEC_SA)
     {
         auto context = std::make_shared<CounterContext<sai_macsec_sa_stat_t>>(context_name, SAI_OBJECT_TYPE_MACSEC_SA, m_vendorSai.get(), m_statsMode);
+        context->always_check_supported_counters = true;
         context->use_sai_stats_capa_query = false;
+        context->dont_clear_support_counter = true;
         return context;
     }
     else if (context_name == COUNTER_TYPE_FLOW)

syncd/FlexCounter.h

@@ -59,6 +59,7 @@ namespace syncd
         bool use_sai_stats_ext = false;
         bool double_confirm_supported_counters = false;
         bool no_double_check_bulk_capability = false;
+        bool dont_clear_support_counter  = false;
     };
     class FlexCounter
     {