Run Grow_restart/Grow_continue when assembling the content of a container.

Run Grow_restart/Grow_continue when assembling the content of a container.

As containers can now grow, we need to use both Grow_restart (to
replay any backup-file) and Grow_continue when assembling the content
of a container.

Note that we don't pass a backup-file when doing incremental assembly.
If such is needed in that case, the assembly will fail.

To restart such arrays, explicit assembly is required.

Signed-off-by: NeilBrown <neilb@suse.de>