[Catalyst] Improve observer mechanism for binding helper

Improvements:
  - Make PersistentPreference.storage is invoked only once during
    binding.
  - Instead of registering an *any* key listener for each storage,
    use per key listeners. It provides another way to support a
    preference has different hierarchy key and datastore key.

Bug: 332201912
Flag: com.android.settings.flags.catalyst
Test: manual
Change-Id: Iaf93d4de6284480391699961ae3d05714212af68