Run per procstate CPU time-in-state tracking on the main thread

Procstate tracking will now be enabled unconditionally
when eBPF is supported by the kernel. Otherwise, it will be disabled.

Bug: 197162116
Test: atest FrameworksCoreTests:BatteryStatsTests

Change-Id: I200ef51b92aa19d42a10966aa6fea6f99d741f3f