Add Region Sampler to Lockscreen Smartspace

This change adds region sampling to the views for lockscreen
smartspace. It also modifies how the region sampling instance
is created. The clock parameter is replaced with an interface
that specifies how the updating of colors should be done. This
allows for a more generalized usage of the region sampling
instance class.

Bug: 202758428
Test: atest LockscreenSmartspaceControllerTest
Change-Id: Id890309c95eab1251d09485ce560e1eae5c15900