Prevent empty recents going home when splitting with taskbar present

* Recents is empty, so it thinks we need to go home
* Split selection state prevents that, since second app can be
choosen from taskbar

Fixes: 260024461
Test: Recents still goes home when taskbar not present and
has no recent tasks. Doesn't go home when split with a single task;
second task launches correctly from taskbar

Change-Id: Ib5fc7989c66c5efccde53ea48319f9669cd664e2