Improve the robustness of updateNonIndexableKeys

- Isolate preference controller crash in the same page
  Current if one search item throw exception, entire page's search will
  broken, can isolate issue by controller to improve.

- Expose preference controller crash in debuggable build
  Current the search index exception is silently ignored, expose the
  exception in debuggable builds to expose issue earlier.

- Change default to hide items instead of shown when crash

Fix: 352455031
Fix: 352455432
Fix: 352455540
Flag: EXEMPT bug fix
Test: manual - Settings Search
Change-Id: I2cdbd58543be8fe6617e42d9c02789791186f53b