fixing subscription id issue (#6812)

Author: Zim Kalinowski

specification/alertsmanagement/resource-manager/Microsoft.AlertsManagement/preview/2019-05-05-preview/AlertsManagement.json

@@ -922,10 +922,11 @@
   "parameters": {
     "subscriptionId": {
       "name": "subscriptionId",
-      "description": "Subscription credentials which uniquely identify Microsoft Azure subscription. The subscription ID forms part of the URI for every service call.",
-      "type": "string",
       "in": "path",
-      "required": true
+      "required": true,
+      "type": "string",
+      "description": "The ID of the target subscription.",
+      "minLength": 1
     },
     "resourceGroupName": {
       "name": "resourceGroupName",

specification/alertsmanagement/resource-manager/Microsoft.AlertsManagement/stable/2019-06-01/SmartDetectorAlertRulesApi.json

@@ -616,7 +616,8 @@
       "in": "path",
       "required": true,
       "type": "string",
-      "description": "The Azure subscription id."
+      "description": "The ID of the target subscription.",
+      "minLength": 1
     },
     "ResourceGroupNameParameter": {
       "name": "resourceGroupName",