Default Flow: UI enhancements

[AkhileshNegi]

Is your feature request related to a problem? Please describe.
In the Organization setting for default flow to set default flow to be active for 24hrs, one uses time as 12:01 AM to 11:59 PM which works, but can we add an option to make it all-day

Describe the solution you'd like
After selecting the flow as the default option we can set 2 options
1. set time and all day with all day as the default option.

2(a) If the user select set time we give the option to enter start time and end time

2(b) If the user select all day we don't give any option

Screenshot

[abhi1203]

Maybe we can update it to this flow: https://www.sketch.com/s/ba323b85-11d7-4687-8a19-681a32132bab/v/Z4oe3J/a/R1d4R48/play/