Cache mechanism for Storage page with work profile

Apply a cache mechanism to prevent the flicker problem from entering
Storage page.

Bug: 191117970
Test: manual test
1) Create a work profile with TestDPC
2) The loading spinner will be shown when entering Storage page after
   the first boot.
3) Back to Settings homepage and switch back to Storage page, the
   loading spinner shouldn't be shown.
4) The preference order shouldn't be updated after changing the storage
   size.

Change-Id: I518679f90c63e12f61f08d08d5ed3f3900825be2
Merged-In: I518679f90c63e12f61f08d08d5ed3f3900825be2
(cherry picked from commit cda892df)