Update Android Apps to work with GN.

This also includes the removal of an old example whose instructions
are not compatible with GN.

BUG=skia:6009

Change-Id: I2807829ca12c19292ae0f5a7ea250ed453f9a182
Reviewed-on: https://skia-review.googlesource.com/5620
Commit-Queue: Derek Sollenberger <djsollen@google.com>
Reviewed-by: Mike Klein <mtklein@chromium.org>
23 files changed