Do not animate indicator if current type is no indicator

ag/31885858 added logic to show the indicator as part of the drag to desktop transition.
In case of bubbles the initial state is no indicator. Which can't be
animated in.
Add a check to ensure that we only animate if an indicator exists.

Bug: 401158358
Test: start drag from app handle on foldable
Flag: EXEMPT trivial bugfix
Change-Id: I0752024ceb2f0f06cc7c67c377cd55f891d14adf