libgui: Check slot received from IGBP in Surface

Checks that the slot number received from mGraphicBufferProducer in
Surface::dequeueBuffer is on the interval [0, NUM_BUFFER_SLOTS) to
protect against a malicious BnGraphicBufferProducer.

Bug: 36991414
Change-Id: I1a76fd1bcce1c558f1c0c30f03638278288ed4fa
(cherry picked from commit 90ce2a9c1d3af422c66b4061805831cb208263d8)
1 file changed