service: ignores subresource queries for service requests

S3 ignores subresource queries for service requests.  For example, the
following request is handled as a GET Service API.

  GET /?acl
  Host: s3.amazonaws.com

This patch addresses the behavior.

Change-Id: I50f3e391048a3a69bc49980212693c1f85bd9d4f
Merge "service: ignores subresource queries for service requests"