Merge "libvulkan: Use a stub HAL when no real Vulkan HAL is present" into nyc-dev
am: 9ffa1a4

* commit '9ffa1a4da16edc23067070f5605917ddd57739e8':
  libvulkan: Use a stub HAL when no real Vulkan HAL is present

Change-Id: Id0993d467fcc234c85cbec3cda3db7fe791dab2c