Add Egress description more clearly

Egress value is emit per minute per Streaming Endpoint services. It's not all of total Streaming Endpoint services.

Author: dahatake

articles/media-services/latest/media-services-metrics-diagnostic-logs.md

@@ -60,7 +60,7 @@ The following Media Services [Streaming Endpoints](https://docs.microsoft.com/re
 |Metric name|Display name|Description|
 |---|---|---|
 |Requests|Requests|Provides the total number of HTTP requests served by the Streaming Endpoint.|
-|Egress|Egress|The total number of egress bytes. For example, bytes streamed by the Streaming Endpoint.|
+|Egress|Egress|The total number of egress bytes total per minute per Streaming Endpoint.|
 |SuccessE2ELatency|Success end to end Latency|Time duration from when the Streaming Endpoint received the request to when the last byte of the response was sent.|
 
 ### Why would I want to use metrics?