Update system setting page subtext

- Move android version from about phone subtext to system update
- Updates strings for autofill, keyboard & input, factory reset, swipe
  for notification
- Add a new pref category for spell checker and personal dictionary
- Display "None" if any default app is not selected
- Display current keyboard type as language subtext

Bug: 36395109
Test: make RunSettingsRoboTests
Change-Id: Id6ca94ea31e55f1c1ec04e47dcf657a25c35c7fe