Fix OS queries for API v20 w/parameters

OS parameters is a list of tuples, so we can't pass it directly to
utils.NiceSort, hence we use a sort key.

This was not detected in QA since QA only tests API v10 :(

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>