am 1f4dd5d6: Merge change 8553 into donut

Merge commit '1f4dd5d6ca82bee7c2ac257d61b373f80dcc1354'

* commit '1f4dd5d6ca82bee7c2ac257d61b373f80dcc1354':
  AI 150106: Add gcc/gmake/cygwin details to NDK sys requirements
  AI 150083: Minor updates to the ndk docs based on approved messaging.
  AI 150055: In Icon Guidelines doc, remove example icons that are not accessible to apps.
  AI 150054: Misc changes for the sdk/devsite docs
  AI 150008: update the Google IO announcement, point to session videos.