SystemUI: fix screentimeout tile icon disappearing

While going away from the detail view, sometimes it wasn't able to
refresh it's state, resulting in the icon not showing and then appearing
suddenly.

Ref: CYNGNOS-2056

Change-Id: I9a634cc4c774c78dc7316619db446f4ea6c2c79f
Signed-off-by: Roman Birg <roman@cyngn.com>