Fix black screen when recents finished after split

Due to split screen might active but in background, we should check
isVisible rather than isActive in mixed handler.

Add more dump info in this CL too for debug convenience.

Fix: 279754733
Test: manaul
Test: pass existing tests
Change-Id: Icb7ba7d1118cd4da84a9ed2509ba8a8f2323b5a3