Function UpdateInitialDate

UpdateInitialDate(datePickerId: string, date1: string, date2?: string): string
Function that will update the InitialDate for a given DatepickerId When: SingleDate => Date1 = InitialDate => Date2 = Ignored!
```
    RangeDate
        => Date1 = InitialStartDate
        => Date2 = InitialEndDate
```
Returns
Response Object as a JSON String
Parameters
- datePickerId: string
- date1: string
  
  The value for the date1
- Optional date2: string
  
  The value for the date2
Returns string
- Defined in OutSystems/OSUI/Patterns/DatePickerAPI.ts:279