am 3bee5af8: Battery stats: start removing last stats, keep total discharge.

Merge commit '3bee5af8162c177f8c8f4199489a401058ab26a9' into gingerbread-plus-aosp

* commit '3bee5af8162c177f8c8f4199489a401058ab26a9':
  Battery stats: start removing last stats, keep total discharge.