Fix quick switch in between two split pairs crash

Launcher always receive recent animatino start callback before
onStageTaskChanged callback, which result to not able to identify the
correct animate targets to animate. Update to fetch animate target from
wrapped remote animation target directly.

Fix: 236226779
Test: quick in between two split pairs won't crash
Change-Id: Ic10db086256b4a1ed53e5a3becb6fa9114df74ec