vndk-def: Add eligible list update tool

This commit adds a tool to update eligible list datasets from
make_vars-$(TARGET).mk and module-info.json.

Test: ./tools/update_dataset.py \
  -o out.csv \
  --make-vars ${OUT_DIR}/soong/make_vars-$(TARGET).mk \
  --module-info ${ANDROID_PRODUCT_OUT}/module-info.json \
  old-eligible-list.csv

Change-Id: Ic6e79b835528703f164db81e8545a90651bbbdc7