Fix concurrency in BATTERY_USAGE_STATS_* statsd atom generation Bug: 229906525 Test: atest --rerun-until-failure 100 FrameworksServicesTests:BatteryStatsManagerTest Change-Id: Ib2d8ab6df40776c7cd2b5852bd956a3f9285b486 (cherry picked from commit 2a510708a117c9efe9102a623988c695aecc6fcb)