Description of problem:
User is not able to set a default value for items Datepicker and Timepicker.

Version-Release number of selected component (if applicable):
5.9.0.19

How reproducible:
Always

Steps to Reproduce:
1. Navigate to Automation -> Automate -> Customization; Service Dialogs; Configuration -> Add a new Dialog
2. Add the Datepicker and the Timepicker item to the new Dialog
3. Edit one of the items; there is no "Default value" field
4. For Datepicker, try to select a date
5. For Timepicker, try to select a date and a time
6. Save the Dialog
7. Notice the values didn't get saved

Actual results:
No "Default value" field when editing Timepicker or Datepicker item; when trying to set a default value from the edit screen, it doesn't get saved or displayed

Expected results:
There should be "Default value" field when editing Timepicker or Datepicker item; or the values given on the edit screen should persist and be considered as default

Additional info: