Shift to measure per-userId OBB directories.

They're now isolated per user, and no longer merged together.

Bug: 128331327
Test: atest android.appsecurity.cts.StorageHostTest#testVerifyStats
Test: atest android.appsecurity.cts.StorageHostTest#testVerifyStatsMultiple
Change-Id: Iaf9243c00114a5a4e102bc0398f5e54c5d4df43e
3 files changed