Fix StatsCompanionService pull on bucket ends

+ change StatsPullerManager internal time units to be consistent
+ use series of alarms for pullers, instead of use setRepeating

Bug: 76223345
Bug: 75970648
Test: cts test
Change-Id: I9e6ac0ce06541f5ceabd2a8fa444e13d40e36983
16 files changed