Fix the StackScrollAlgorithmTest on cf tablet

Make the StackScrollAlgorithmTest use dimens values instead of hardcoded
pixel values, to make it reliable across different screen densities.

Bug: 306183683
Test: atest StackScrollAlgorithmTest
Test: abtd runs on different targets
Change-Id: I3c568bf283ce2980071e343f38ad4281108ac0a2
1 file changed