core: synchronize lun device size on refreshLunsInfo

SyncLunsInfoForIscsiStorageDomainCommand:
When detecting a mismatch in LUN device size,
store the updated size data in DB.

* Added 'updateLUNsDeviceSize' method to LunDAO.
* Updated storages_san_sp.sql accordingly.

Note: the command is invoked when activating iSCSI SD.

Change-Id: I618880c7b49c226e39f0a0830f1d4f9b71a5f304
Bug-Url: https://bugzilla.redhat.com/961532
Signed-off-by: Daniel Erez <derez@redhat.com>