Wakelock tracking in BatteryStats relies on the the isolated uid map
when tracking wakelocks from isolated uids. The map needs to keep the
isolated uid while it still has a wakelock.
Bug: 194414351
Test: atest BatteryStatsNoteTest
Change-Id: I5e51f5f90191829d12fb080169520d9827b9906c
(cherry picked from commit 83c0928c34)
Merged-In: I5e51f5f90191829d12fb080169520d9827b9906c