"Files" property is mandatory to provide in properties for this Microsoft.Web sites/functions template

azure-quickstart-templates/201-logic-app-transform-function/azuredeploy.json
[201-logic-app-transform-function](https://github.com/Azure/azure-quickstart-templates/blob/master/201-logic-app-transform-function/azuredeploy.json)

### Issue Details
When I try to use this template and removed the "files" from the properties the function doesn't display in the FunctioAPP
### Repro steps (*if necessary, delete otherwise*)
1. Copy the template and paste it in the editor of Custom deployment

2. Remove files from the properties
3. deploy and see the function added to the function app
4. function is not displayed in the "functions" section

Start with azure-quickstart-templates/201-logic-app-transform-function/azuredeploy.json and reproduce the Custom deployment described in the issue after removing the files property. Compare the resulting Function App with the template deployment; done means the template's function is displayed in the Functions section without the reported failure.

Written by the indexing model from the issue text.