Cache mechanism for Storage page

- Use SharedPreference to cache the size info
- Improve the flicker problem on Documents & other preference
- The jobs are destroied on onPause to prevent the jobs being
  restarting when back to Storage page
- Enable progress bar animation for each storage item

Bug: 191117970
Test: manual test
1) The loading spinner will be shown when entering Storage page
   at first time.
2) Back to Settings homepage and switch back to Storage page, the
   loading spinner shouldn't be shown.
3) Click each preference in the Storage page and switch between these
   pages, the size info should be updated if something removed and the
   order of preference shouldn't be changed.

Change-Id: I75533742a025dc61116207285a894ee728d0af68
Merged-In: I75533742a025dc61116207285a894ee728d0af68
(cherry picked from commit 77775a66)