add consume/produce type (#12773)

Author: chenjianfei2017

specification/notebooks/resource-manager/Microsoft.Notebooks/preview/2019-10-11-preview/notebooks.json

@@ -9,6 +9,12 @@
   "schemes": [
     "https"
   ],
+  "consumes": [
+    "application/json"
+  ],
+  "produces": [
+    "application/json"
+  ],
   "security": [
     {
       "azure_auth": [