[MaterialDatePicker][MaterialTimePicker] Support Fragment Result API

Is your feature request related to a problem? Please describe.

The current API of both MaterialDatePicker and MaterialTimePicker only supports listeners, such as MaterialTimePicker.addOnNegativeButtonClickListener(listener), which unfortunately do not persist across configuration changes.

Describe the solution you'd like

Both MaterialDatePicker and MaterialTimePicker should support Fragment Result API so that the dialogs work properly even after a configuration change has occurred.

Describe alternatives you've considered

Both classes are final so adding this behavior ourselves is not possible.

I also considered extracting the Dialog logic and creating a DialogFragment myself so that we can set Fragment results.

Additional context

Because of this oversight, we decided not to use the MaterialDatePicker because it can not be implemented reliably. We continue to use android.app.DatePickerDialog which extends AlertDialog so that we can wrap it in a FragmentDialog which allows us to implement Fragment Result API ourselves.

Inizia con le API dei listener di MaterialDatePicker e MaterialTimePicker e con la documentazione collegata di Android Fragment Result API. Definisci come ciascuna finestra di dialogo espone i risultati durante i cambiamenti di configurazione, quindi verifica che entrambi i tipi di picker conservino e forniscano tali risultati dopo la ricreazione.