Have the framework setup android defines for including vulkan.h

We're moving skia to place where it has its own vulkan header and
the clients have theirs. So this sets up the VulkanManager to be
able to handle including vulkan.h how it wants to.

Test: manual building and running

Change-Id: I0818d2fc607bf8a265bf6ddf1e2f737d1228131a
1 file changed