Updated Notification Hover colors to account for colorized notifications

Notification background hover layer now uses one of three color state lists:
light colorized notification hover color, dark colorized notification hover color or the default notification hover color
for uncolorized notifications

Fixes: 314091474
Test:  create a notification -> hover with mouse -> ensure notification has a hover effect;
create a colorized notification -> hover with mouse -> ensure notification has a hover effect without losing its initial color.
Flag: NA
Change-Id: Ib9a1c8ef7b8ac1efba9c0f108208539ff4daceee