UserPreferencesBottomSheetDialogFragment does not survive configuration changes

[LubomirGanchev]

Describe the bug

Test app crash when device is rotated while the user settings bottom sheet dialog is opened.

How to reproduce?

1. Open book
2. Open user settings bottom sheet
3. Rotate the device

Readium version

2.4.0

Android API version

33

Additional context

java.lang.RuntimeException: Unable to start activity ComponentInfo{org.readium.r2reader/org.readium.r2.testapp.reader.ReaderActivity}: androidx.fragment.app.Fragment$InstantiationException: Unable to instantiate fragment org.readium.r2.testapp.reader.preferences.UserPreferencesBottomSheetDialogFragment: could not find Fragment constructor