snapshot: use volume's brick_ids for the snaps

brickinfo->brick_id was introduced to establish persistence of client xlator
names and AFR chanelog attributes (http://review.gluster.org/7155). The
snapshot volumes must also use the same IDs during snapshot create and
restore to maintain persistence.

Change-Id: I13d66d19b63520061ba9ec5f0ce661cf3b9eeafe
BUG: 1066778
Signed-off-by: Ravishankar N <ravishankar@redhat.com>
Reviewed-on: http://review.gluster.org/7477
Reviewed-by: Vijaikumar Mallikarjuna <vmallika@redhat.com>
Reviewed-by: Avra Sengupta <asengupt@redhat.com>
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>