You can realize a modal bottom sheets using a BottomSheetDialogFragment.
The BottomSheetDialogFragment is a modal bottom sheet.
This is a version of DialogFragment that shows a bottom sheet using BottomSheetDialog instead of a floating dialog.
Just define the fragment:
public class MyBottomSheet...
BottomSheet DialogFragment opens up in STATE_COLLAPSED by default. Which can be forced to open to STATE_EXPANDEDand take up the full device screen with help of the following code template.
@NonNull @Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
BottomSheetDialog dialog = ...