Fix container details test's starting environment

When the unit tests are run in an environment like the functional
tests, where the accurrate size in listings switch is on, we need to
sure that the tests that verify the behavior when it is off run in
that state.

Change-Id: I9f3ef90af7ef4edc698e2b8b7f016e6aaa7fac98
Signed-off-by: Peter Portante <peter.portante@redhat.com>
Reviewed-on: http://review.gluster.org/5703
Reviewed-by: Luis Pabon <lpabon@redhat.com>
Tested-by: Luis Pabon <lpabon@redhat.com>