synapse web activity update: Disable Cert Validation property. (#18294)

* Add pipeline policy and ElapsedTime Policy

* adding missing objects

* fix schema validation

* fix prettier issues

* add disable cert validation in webactivity

Co-authored-by: Kalyan C Kesireddy <kalyanke@microsoft.com>

Author: kalyanrk61

specification/synapse/data-plane/Microsoft.Synapse/preview/2021-06-01-preview/entityTypes/Pipeline.json

@@ -5990,6 +5990,10 @@
           "description": "Authentication method used for calling the endpoint.",
           "$ref": "#/definitions/WebActivityAuthentication"
         },
+        "disableCertValidation": {
+          "type": "boolean",
+          "description": "When set to true, Certificate validation will be disabled."
+        },
         "datasets": {
           "type": "array",
           "description": "List of datasets passed to web endpoint.",