Add AWS Metering service support (#15290)

model/system.go

@@ -31,6 +31,8 @@ const (
 	SYSTEM_WARN_METRIC_NUMBER_OF_ACTIVE_USERS_500 = "warn_metric_number_of_active_users_500"
 	SYSTEM_WARN_METRIC_NUMBER_OF_POSTS_2M         = "warn_metric_number_of_posts_2M"
 	SYSTEM_WARN_METRIC_LAST_RUN_TIMESTAMP_KEY     = "LastWarnMetricRunTimestamp"
+	AWS_METERING_REPORT_INTERVAL                  = 1
+	AWS_METERING_DIMENSION_USAGE_HRS              = "UsageHrs"
 )
 
 const (