Fix translationZ matrix computation

bug:14259972

Ensure that translationZ is applied for true3dTransform property
transformations, even if the node doesn't have any other
transformation properties set.

Additionally, use fuzzy compare for translationZ, similar to
rotationX/Y, since they're expenive to leave set in rounding error
cases.

Change-Id: Idafa4423cc7751a8f433237b1f576aa7abb74f6e