SurfaceFlinger: Inherit non-transform Scaling from parent.

When a Layer is fixed-size, we may apply additional scaling
to the buffer not accounted for in the transform. This means
that if the WindowManager calls setSize we will scale the parent
surface but not the child surfaces, breaking the contract that
the WM can treat the child surfaces as pixels in the parent.

Test: Included test in Transaction_test.
Bug: 36820947
Bug: 37344435
Change-Id: I5478bad176388fe8e5407379bc36cdfd6600ab97