Add 2 attributes for list_divider_material

We added two attributes for list divider, one gets set up the color of list
divider and the other gets set up the opacity of its color. This
approach facilitates updating the color of the list divider for device
default themes.

Bug: 129943610
Test: visual
Change-Id: Ia319a31e223a86d71720e2dab63dce200ca824df