Use connection_info on resize

During finish_migration the manager calls initialize_connection but doesn't
update the block_device_mapping with the (potentially new) connection_info
returned.

This can cause the bdm to get out of sync, the volume to fail to attach, and
the resize to fail.

Fixes bug #1076801

Change-Id: Ie49ccd2138905e178843b375a9b16c3fe572d1db
Merge "Use connection_info on resize"