enable AAD in test resources (#17351)

Author: maririos

sdk/textanalytics/test-resources.json

@@ -50,6 +50,7 @@
         }
     },
     "variables": {
+        "roleDefinitionId": "[concat('/subscriptions/', subscription().subscriptionId, '/providers/Microsoft.Authorization/roleDefinitions/a97b65f3-24c7-4388-baec-2e87135dc908')]",
         "uniqueSubDomainName": "[format('{0}-{1}', parameters('baseName'), parameters('endpointPrefix'))]",
         "endpointValue": "[format('https://{0}-{1}{2}', parameters('baseName'), parameters('endpointPrefix'), parameters('endpointSuffix'))]"
     },
@@ -66,6 +67,15 @@
             "properties": {
                 "customSubDomainName": "[variables('uniqueSubDomainName')]"
             }
+        },
+        {
+            "type": "Microsoft.Authorization/roleAssignments",
+            "apiVersion": "2018-09-01-preview",
+            "name": "[guid(resourceGroup().id)]",
+            "properties": {
+                "roleDefinitionId": "[variables('roleDefinitionId')]",
+                "principalId": "[parameters('testApplicationOid')]"
+            }
         }
     ],
     "outputs": {