updated etag to eTag (#13968)

Author: maddieminn

specification/consumption/resource-manager/Microsoft.Consumption/stable/2019-10-01/consumption.json

@@ -3013,9 +3013,9 @@
           "type": "string",
           "description": "Resource sku"
         },
-        "etag": {
+        "eTag": {
           "type": "string",
-          "description": "Resource etag."
+          "description": "Resource eTag."
         },
         "properties": {
           "x-ms-client-flatten": true,