Fix AbsListView StrictMode.Span end point on flings.

Noticed after logs showed a ton of false positives, I went back and
looked at the history.  During the review of the previous CL, I
accidentally moved the finish() of the fling animation tracking inside
the PROFILE_FLINGING block, which is normally off.

Re-tested this CL with StrictMode debugging enabled and it now always
propertly resets to 0 animations in flight when no animations are
running.

Change-Id: Ie9746df36e2ec3f82679b20e91e3d93c05b863d4