Dev/kalyanke/webhook activitypolicy (#25365)

* Add pipeline policy and ElapsedTime Policy

* adding missing objects

* fix schema validation

* fix prettier issues

* Change webhook to ExecutionActivity

* change to policy object

* fix comments

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Co-authored-by: Kalyan C Kesireddy <[email protected]>

Author: 2 people

specification/datafactory/resource-manager/Microsoft.DataFactory/stable/2018-06-01/entityTypes/Pipeline.json

@@ -7907,6 +7907,10 @@
           "description": "WebHook activity properties.",
           "x-ms-client-flatten": true,
           "$ref": "#/definitions/WebHookActivityTypeProperties"
+        },
+        "policy": {
+          "$ref": "#/definitions/SecureInputOutputPolicy",
+          "description": "Activity policy."
         }
       },
       "required": [