[DataFactory]Set servicePrincipalId,servicePrincipalKey and tenant to be optional from AzureDataExplorerLinkedServiceTypeProperties (#12755)

Author: Jingshu923

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

@@ -5825,10 +5825,7 @@
       },
       "required": [
         "endpoint",
-        "servicePrincipalId",
-        "servicePrincipalKey",
-        "database",
-        "tenant"
+        "database"
       ]
     },
     "AzureFunctionLinkedService": {