Keep track of discharge while screen is on vs. off. Checkin looks like: 5,0,u,dc,1,1,1,0 The last four numbers are, from left: - Maximum battery drain over time period. - Minimum battery drain over time period. - Battery drain while screen was on. - Battery drain while screen was off. Change-Id: Ie4026a7cc8aabb2a6d47d03d2e278aa51c2d5ddf