Make gralloc0 pass-through mapper handle layers

Gralloc0 does not support layers. This change is needed for Cuttlefish
to pass the GraphicsMapperHidlTest.ValidateBufferSizeBadValue VTS test

Bug: b/132087346
Test: vts-tradefed run commandAndExit vts -m VtsHalGraphicsMapperV2_1Target
Change-Id: I2ed7dae209629d401ccaf2fc0fd992d766b0fa9b
(cherry picked from commit 8b5b9fb5)