update to NDK r17

We haven't done this in a while.

The only interesting change I've noticed so far is that we no longer
need to link libandroid_support when targeting API 21+.

Change-Id: I6506fbe7bd02534f1ea136f2164acab7f44c29e0
Reviewed-on: https://skia-review.googlesource.com/128009
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Mike Klein <mtklein@chromium.org>
8 files changed