Merge "vulkan: fix crash when only non-global layers are enabled" into nyc-dev
am: a101f6a446

* commit 'a101f6a446722697e0ed6afb128829937b90d60a':
  vulkan: fix crash when only non-global layers are enabled

Change-Id: I65baa95e0b00f3fbc136d435c4481256a7e551bd