SurfaceFlinger: Drop input for blacked out layers

If the window will be blacked out on a display because
the display does not have the secure flag and the layer
has the secure flag set, then drop input.

Test: atest libgui_test
Fixes: 200842159
Change-Id: Idfe245b0f0091e0cafc15c83b25a9d0fd7364174
4 files changed