core: Use container id for memory lock in import process.

When importing a VM we use memory lock on the VM in the export domain so
it will not get deleted in the process.

When the import process is being done with clone, a new vm id is generated
and the lock at the end command is being regenerated with the new
VM guid instead of the original one from the export domain.

The proposed fix is to use the container id from the parameters when
generating the shared lock.

Signed-off-by: Maor Lipchuk <mlipchuk@redhat.com>
Bug-Url:  https://bugzilla.redhat.com/998907
Change-Id: Ie849300bdc98020aeca90deeddafd12295e8211a