Allow making API requests as an authenticated user

GitHub's API has a rate limit of 60 requests per hour
for logged out users. In some cases, this might be
too little, and the special page will start displaying
weird results like no valid versions or randomly
missing some.

This enables use of an OAuth2 token, passed via the
"access_token" parameter. This increases the rate limit
to 5000 requests per hour.

Bug: 65852
Change-Id: I1f4ad6d06aaf8b2996f819cacb86171196fbd6a6
Merge "Allow making API requests as an authenticated user"