Make reloading color options thread safe

Use new lists for color options and copy them to avoid
concurrent modification if we get a colors changed
event from the wallpaper while traversing them

Bug: 229684864
Fixes: 229549608
Test: manual
Change-Id: Ida3074742861648c5f4da48c788a7ea8d1fdd6bc
(cherry picked from commit c30bc1f2)