SideBySide2: Fix Reply/Done buttons in add regions

If two comments are placed on different lines in a single add
region the Reply/Done buttons on the first comment were broken.
The breakage was caused by the group's peer being replaced in sideA
by the second group's peer, so the first group's peer was never
attached to CM3.

Always attach both members at the same time, from either map.

Change-Id: Iccce04ef5f8758f35376829140e0e2f308d387a2
2 files changed