Turn on swift log uploading for infra jobs

Dogfood our swift uploading on infra jobs. This will allow us to
compare disk copies to swift. Note that disk copies are served
first if available (unless ?source=swift is in the get params).

Change-Id: Iee52d4f906ae78d3c253055e4e86b3615ccad0af
Merge "Turn on swift log uploading for infra jobs"