Fix InputSurfacesTest.input_respects_scaled_touchable_region_overflow

When there is an overflow while the touchable region is being
transformed, we skip the touchable region calculation, which results in
the touchable region being empty. This means the layer that was
misconfigured will not be touchable, so the touch will go to the
background surface.

Bug: 240566619
Bug: 240437119
Test: atest libgui_test:InputSurfacesTest
Change-Id: I4ec7f2b7544297aa25ee216cbbe1ddf1cd32f9f1