am 4f564cde: Tweaks to download manager API based on API review feedback

Merge commit '4f564cdeb8478f1a20263fc036c74cc4a63145c3' into gingerbread-plus-aosp

* commit '4f564cdeb8478f1a20263fc036c74cc4a63145c3':
  Tweaks to download manager API based on API review feedback