Make transcript mode only scroll to the bottom if the last item is
already scrolled fully to the bottom when the change occurs Before
this, transcript mode would cause a list to scroll to the bottom as
long as the last item in the adapter was visible at all. Long items
would make this behave unexpectedly.
Change-Id: Ia6a52c969ea6d50653cf2b8cd4dc30ba517cf803
0785279dad