add Android builds

I found it simplest to just configure things to build with
the ndk as a sibling directory of skcms.  Easy enough to
set up locally, I think?

Change-Id: I66cd1916678bd6026a472d30d59bad794c3290bd
Reviewed-on: https://skia-review.googlesource.com/95740
Reviewed-by: Brian Osman <brianosman@google.com>
27 files changed