Fix swagger violation for resource health operations definitions (#2863)

Author: HimanshuMisra1

specification/resourcehealth/resource-manager/Microsoft.ResourceHealth/stable/2015-01-01/resourcehealth.json

@@ -493,7 +493,7 @@
             },
             "operation": {
               "type": "string",
-              "description": "Operation."
+              "description": "Operation name."
             },
             "description": {
               "type": "string",

specification/resourcehealth/resource-manager/Microsoft.ResourceHealth/stable/2017-07-01/resourcehealth.json

@@ -509,7 +509,7 @@
             },
             "operation": {
               "type": "string",
-              "description": "Operation."
+              "description": "Operation name."
             },
             "description": {
               "type": "string",