VxLAN Tunnel Counters and Rates implementation (#8369) (#11986)

* Enable flex counters for Vxlan tunnel
* VxLAN Tunnel Counters and Rates implementation  (#8369) (#11986)

Author: dgsudharsan

dockers/docker-orchagent/enable_counters.py

@@ -26,6 +26,8 @@ def enable_rates():
     counters_db.set('COUNTERS_DB', 'RATES:PORT', 'PORT_ALPHA', DEFAULT_ALPHA)
     counters_db.set('COUNTERS_DB', 'RATES:RIF', 'RIF_SMOOTH_INTERVAL', DEFAULT_SMOOTH_INTERVAL)
     counters_db.set('COUNTERS_DB', 'RATES:RIF', 'RIF_ALPHA', DEFAULT_ALPHA)
+    counters_db.set('COUNTERS_DB', 'RATES:TUNNEL', 'TUNNEL_SMOOTH_INTERVAL', DEFAULT_SMOOTH_INTERVAL)
+    counters_db.set('COUNTERS_DB', 'RATES:TUNNEL', 'TUNNEL_ALPHA', DEFAULT_ALPHA)
 
 
 def enable_counters():