tflite: Add Bazel skeleton with empty sample delegate

BUG=b:314854484
TEST=bazel build --config=host_clang \
  //delegate/sample:tensorflowlite_cros_sample_delegate

Change-Id: Ie54f034a16e9c62562284e84c15d35ee349a8d82
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/tflite/+/5267424
Reviewed-by: Tommy Chiang <ototot@google.com>
Commit-Queue: Shik Chen <shik@chromium.org>
Tested-by: Shik Chen <shik@chromium.org>