am f4790e6f: Separate platform files and samples by API level.

Merge commit 'f4790e6f9e47347996e62ecd27ff55b6499cf97a' into gingerbread-plus-aosp

* commit 'f4790e6f9e47347996e62ecd27ff55b6499cf97a':
  Separate platform files and samples by API level.