Add new method to preference controller base for dynamic index.

- Add updateDynamicRawDataToIndex method.
- Implement preference controller index in BaseSearchIndexProvider.

Fixes: 144545478
Test: make RunSettingsGoogleRoboTests -j
      make RunSettingsRoboTests ROBOTEST_FILTER=
      com.android.settings.search.BaseSearchIndexProviderTest
Change-Id: Ibb11002227b280102b45d7c0610eae48ecf4c0f3