These are written in preparation for follow up old-style quotas code
removal that moves the logic for the 'reserved' field from the quota
internals (where it's no longer used) to the API (where it's expected
to be provided until we have a new microversion). These tests will
help catch any unintended change in behavior.
Change-Id: I1f743a8db7d032e09372587622ab64250a05e0f0
93ceb7fb5e