Fix light center position for layers

SkiaLayer::inverseTransformInWindow should be the inverse
matrix of Layer transform. This CL fixes a bug, that matrix
value was not inverted.
This matrix is used in one place: to transform light
center coordinates from device to RenderNode/layer
coordinate space.

Bug: 132758858
Test: Ran test app attached to bug. Manually compared coordinates.
Change-Id: Id8e887276a5296091a8264d7a0b1bcc955620a6a