gralloc: Align protected allocations with the spec

The specification for GRALLOC_USAGE_PROTECTED indicates that
allocations with that flag must be protected by securing with
hardware. If such protection is not possible, the buffer must not
be composited. In our current software only the MM_HEAP is
secured. If we allocate protected buffers from any other heap we
block those from being displayed.

CRs-fixed: 465012
Change-Id: I9d47aba3d28192db3fcc394fd6b38efe42ae118b
2 files changed