Wear Preview, auto, tv, versions project metadata.

b/31771704 b/31903798 b/31773716

Staged:
https://android-dot-devsite.googleplex.com/about/versions/nougat/index.html
https://android-dot-devsite.googleplex.com/index.html
https://android-dot-devsite.googleplex.com/wear/preview/index.html

Change-Id: I639b3d168b839745669787c56b44c28fa85252d9