Revert "SystemUI: disable statusbar time refresh when screen off"

This reverts commit 17e345d6a1fd47fef355ebdd55e6215781fa180d.

Change-Id: I2a18da40a77a9d59b116226910c64ff304f051a5
Merge "Revert "SystemUI: disable statusbar time refresh when screen off"" into pac-4.4