systemui: improve DessertCaseDream immersive mode exit

Change-Id: I9d68e3f2e63467ae2f842a99e0071b562dfb6b15
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>
Revert "AOSB Recent App iPhoney UI"

This reverts commit 94fbaf0da20356e0fa8d7263e18752ec1a03a4e6.