Reserve HWC for VDS for WFD use case. During WFD usecase, sink usage
will contain GRALLOC_USAGE_PRIVATE_WFD flag.
When HWC is avoided, all virtual displays are composed using GLES.
This means that GLES composes directly into the sink buffer and
signals the consumer. Furthermore, it is expected that any color
conversion will be handled on the consumer side.
CRs-Fixed: 908380
Change-Id: I93ff54c79ece788b6caf3f4172835d8ac1362f62
Add DisplayUtils class which uses the custom implementations
of ExLayer, ExSurfaceFlinger, ExHWComposer,
and ExVirtualDisplaySurface classes if needed
Change-Id: Ibdd8da5d3d0d602f42b76a15d0994c6aa98bee3f
