[Catalyst] Migrate AmbientDisplayAlwaysOnPreferenceController

As the preference is exported as external settings, for safety, do not
update the preference key with datastore key. As a workaround, manage a
mapping between preference hierarchy key and datastore key.

Bug: 372307567
Flag: com.android.settings.flags.catalyst_lockscreen_from_display_settings
Test: devtool
Change-Id: I56126485061859b41216cd23b8e1caf63823a1ec