Smartspace - Allow primary card colors to be updated

This is largely for both AOD and lockscreen, while may have different
colors than launcher. Particularly for AOD, we need to transition to a
WHITE color. Set a primary text color, with expectations that a
secondary color will later be set in order to support cards with
various background colors.

Fixes: 185211979
Test: manual, change to AOD <-> LS
Change-Id: I36fb8e5cfcbac1ec999b2b9df08f42d47507990f