Merge "Android Studio 2.1 release notes and downloads." into mnc-mr-docs
am: c939dd0

* commit 'c939dd0f9c692cffd2d42ca7e47e11849ea484c3':
  Android Studio 2.1 release notes and downloads.

Change-Id: I7d1064613d65cf605ff7dde60386a127a31d618f