LU-9826 test: Recreate disk2_7-zfs image to have a bigger file system

LU-9826 test: Recreate disk2_7-zfs image to have a bigger file system

Increase 2.7 zfs file system size and move conf_sanity
test_32b out of the ALWAYS_EXCEPT list

Test-Parameters: ostfilesystemtype=zfs mdtfilesystemtype=zfs \
testlist=conf-sanity

Change-Id: I61e40bc495b06fcc73d4d6d5707433686984bcc7
Signed-off-by: Wei Liu <wei3.liu@intel.com>
Reviewed-on: https://review.whamcloud.com/28464
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Nunez <james.a.nunez@intel.com>
Reviewed-by: Alex Zhuravlev <alexey.zhuravlev@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>