Fix not hiding soft-input when quick switch start

After Ia6722e1cb, soft-input hiding logic has been migrated to
setAnimationTargetsBehindSystemBars. However, Launcher invokes
setAnimationTargetsBehindSystemBars when the center most task changed
while in quick switch. Update to hide the soft-input when recents input
consumer gains focus.

Fix: 193990612
Test: enter split screen and verified quick-switch will hide soft-input
      immediately.
Change-Id: Ibfcd48e623336c4690b71c4db0ce1ad8f5b26fc9