fucshia: Fix build.

This changes some #ifndef VK_USE_PLATFORM_FUCSHIA_KHR
to #if defined(VK_USE_PLATFORM_ANDROID_KHR) || defined(__linux__)
per comments in aosp/1989229; also it adds back #ifdef guards for
|mRendernodeFd| in impl::ResourceTracker.

TEST: fx build
Change-Id: I6ee26300dcdefe498317dbdf253156bd44320a4e
1 file changed