Persist user-agnostic lastTimeAnyComponentUsed in disk

Persist the user-agnostic lastTimeAnyComponentUsed usage stats in disk.

Bug: 183462940
Test: atest UsageStatsServiceTest
Test: atest UserStatsPersistenceTest
Test: atest CtsUsageStatsTestCases:UsageStatsTest

Change-Id: Ibe946f8e9fd9fa7d9ba546da67a6040c00e0f9ea
4 files changed