Add fields for system boot reason (main, sub, detail) to WW atom

So instead of logging:
* system_reason = "bootloader,reboot,userrequested"

... we will log:
* system_main_reason = "bootloader"
* system_sub_reason = "reboot"
* system_detail = "userrequested"

Change-Id: I881d9a73fea16219796dc97fd78ecac712032980
Bug: 380017314
Flag: EXEMPT see b/380017314
1 file changed
tree: 39ab6c2cd608aaab3c51a4f32bf24b558e477fd0
  1. stats/
  2. OWNERS