storaged: add --force option to dumpsys

This option forces storaged to generate io usage report since last
report. This is for testing purpose so that we can run some app and
get the app's IO usage right away instead of waiting an hour for next
report.

Bug: 34198239
Bug: 34845096
Change-Id: I9cd217df37a9b6c8f383eb25d41602e8e8c8f9ba