Reposition Undo Bar if user enters into conversation before or while the
animation is running.

Give a little bit of margin to the Undo Bar when it is not shown in the
conversation to match the amount of empty space under the Undo Bar while it is
shown in the conversation.

Bug: 7418034
Change-Id: I7f4333b9bc89e8c55a938c8aeb37026abc419a1a
6 files changed