Many media files and source code files were marked as executable in Git.
Remove those.
Also a shell script and python script were not marked as executable.
Change-Id: Ieb51bafb46c895a21d2e83696f5a901ba752b2c5
This directory is not included in the final docs output, but is
merely here as a "master" source for the downloadable bits that we
upload and serve from elsewhere, such as from Google Cloud Storage.
Change-Id: I181438f9ec4513cf2e49455803bbe434c8f29d36