Don't apply filter in readback, when there is no scaling

Fix check for scaling in SkiaOpenGLReadback: old code was not
taking into account that matrix rotation swaps width/height.

Test: Passed PixelCopyTest#testWindowProducerCopyToRGBA16F
Bug: 110097060
Bug: 111776948
Change-Id: I0d26416fa72a026bc376417773d5a73548b1f1a5
Merged-In: I0d26416fa72a026bc376417773d5a73548b1f1a5
(cherry picked from commit d50edd00)
(cherry picked from commit ee7b63aa646c937e326ac5f39f07f724020533bb)