Inconsistent Custom schedule default values for SLA create and SLA edit actions

Problem description: The default values of the custom schedule for weekdays are different in SLA create and SLA Edit forms. If we create a new SLA and switch to custom schedule, then by default the schedule will be set to working days from 8:00 till 17:00, but when the same is done in the SLA edit form, custom schedule is empty by default.

Steps to reproduce:

1. Navigate to Services => SLA
2. Press "Create SLA" button
3. Fill in all mandatory fields in the opened dialog
4. Switch "Schedule" radio button to "Custom" and check the default values
   1. Note that the schedule is active on working days from 8:00 till 17:00 bu default
5. Switch back to "24x7" schedule and submit the form
6. Open the created SLA in edit mode
7. Swith Schedule radio button to "Custom"

Result: in Edit mode, the custom schedule is empty by default
Expected: same as in create mode, in edit mode the default custom schedule values should represent work days form 8:00 till 17:00.

Example: