pixelstats: Add battery usage stats

This sends accumulated time spent above different SOC and temperature
levels on the device. This will sent a burst of events based on what the
swelling_data sysfs node provides.

eldar/142490839

Bug: 230501230
Test: logcat | grep pixelstats
Signed-off-by: Jenny Ho <hsiufangho@google.com>
Merged-In: If54a545503dcb47b9214ef0117acdf060c586035
Change-Id: I6358d02d8ae8a4c0c21b20cc04c2e75a46754e92
5 files changed