Only enumerate display_timing when present timestamp supported

Test: CTS and cube demo.
Bug: 36887025

Vulkan should only enumerate the VK_GOOGLE_display_timing extension if
the device supports reliably returning the present timestamp.  Vulkan
will determine this by reading a property that SurfaceFlinger will set
(based on the HWC2::Capability::PresentFenceIsNotReliable capability).

Change-Id: I6025be5f9120a8f02f228b8437b64be4ff8cfb17