Run the versioner as part of the build.

Run the versioner as part of the build.

Running this periodically and checking in the results is not working
out, since the result is just that I'm having to spend a lot of time
cleaning up the headers every time I need to update them in the NDK.

Run the versioner as part of the build instead. This way bionic
header changes behave like the rest of the NDK headers and will
affect NDK builds in the platform *immediately*.

Remove the preupload hook for the versioner since it's part of the
normal build now.

The versioner's dependencies directory needs to be moved because
soong won't let us try to do things outside our module's directory
(in this case libc).

Unfortunately this means we need to build the versioner for Darwin,
because we now need it to perform a platform build.

Test: make checkbuild
Bug: None
Change-Id: Icdab8a962354d9e945072dc3f806baea376c8db4