am 3b8381e1: am 7bb37c87: am 0480d5d8: Merge "docs: Android SDK 21.1.0 Release Notes" into jb-mr1-dev

# Via Android Git Automerger (2) and others
* commit '3b8381e1ed71258957718b8cc8dca46ee587c0fe':
  docs: Android SDK 21.1.0 Release Notes