Dedupe updates to the home handle tint

- The dark intensity & home handle was updating but due to the
  interpolator used and the long duration of the animation, the
  rounded rgb/alpha values didn't actually change between every
  animation frame.

Bug: 143565744
Test: Trigger nav bar handle tint change, ensure no unnecessary updates
Change-Id: I44a403f381b4216d07cecb74097e52c4abc85465