fix pipeline errors

Author: zhaomuzhi

specification/machinelearningservices/resource-manager/Microsoft.MachineLearningServices/stable/2021-01-01/examples/createWorkspace.json

@@ -135,7 +135,6 @@
           "applicationInsights": "/subscriptions/00000000-1111-2222-3333-444444444444/resourceGroups/workspace-1234/providers/microsoft.insights/components/testinsights",
           "storageAccount": "/subscriptions/00000000-1111-2222-3333-444444444444/resourceGroups/accountcrud-1234/providers/Microsoft.Storage/storageAccounts/testStorageAccount",
           "discoveryUrl": "http://example.com",
-          "creationTime": "2017-03-01T23:14:37.0707808Z",
           "friendlyName": "HelloName",
           "description": "test description",
           "encryption": {

specification/machinelearningservices/resource-manager/Microsoft.MachineLearningServices/stable/2021-01-01/examples/listNotebookKeys.json

@@ -8,8 +8,8 @@
   "responses": {
     "200": {
       "body": {
-        "primaryAccessKey": "<primaryAccessKey>",
-        "secondaryAccessKey": "<secondaryAccessKey>"
+        "primaryAccessKey": null,
+        "secondaryAccessKey": null
       }
     }
   }

specification/machinelearningservices/resource-manager/Microsoft.MachineLearningServices/stable/2021-01-01/examples/listStorageAccountKeys.json

@@ -8,7 +8,7 @@
   "responses": {
     "200": {
       "body": {
-        "userStorageKey": "<userStorageKey>"
+        "userStorageKey": null
       }
     }
   }

specification/machinelearningservices/resource-manager/Microsoft.MachineLearningServices/stable/2021-01-01/examples/listWorkspaceKeys.json

@@ -8,7 +8,7 @@
   "responses": {
     "200": {
       "body": {
-        "userStorageKey": "<userStorageKey>",
+        "userStorageKey": null,
         "userStorageResourceId": "/subscriptions/aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee/resourceGroups/ragargeastus2euap/providers/Microsoft.Storage/storageAccounts/testdemoworkazashomr",
         "appInsightsInstrumentationKey": null,
         "containerRegistryCredentials": {
@@ -26,8 +26,8 @@
           ]
         },
         "notebookAccessKeys": {
-          "primaryAccessKey": "<primaryAccessKey>",
-          "secondaryAccessKey": "<secondaryAccesskey>"
+          "primaryAccessKey": null,
+          "secondaryAccessKey": null
         }
       }
     }