Make smart idle maint update write amount record every period

Now, when the condition doesn't meet, smart idle maintenance service
doesn't update write amount record. Fixed it, since it should be updated
every period.

Bug: 241601216
Test: check smart idle maint log of StorageManagerService
Signed-off-by: Daeho Jeong <daehojeong@google.com>
Change-Id: I339109fcaa821620a3b9b4b8c49e25fd18d03cf3
Merged-In: I339109fcaa821620a3b9b4b8c49e25fd18d03cf3