Pick the primary color as the best color to use.

Previously, the best color was picked by checking the colors
against the blacklist. The logic was for picking the best color
was broken When the blacklist was removed for
b/124180048.

Fixes: b129762944
Test: New test points added to TonalTest.java
Change-Id: Ie51806735910bb40e5e66d7baf545ea213e4a01e