Add art-bootclasspath-fragment

Adds bootclasspath_fragment for the art module alongside the existing
boot_image which will be removed in a follow up change once prebuilts
have been updated.

Bug: 177892522
Test: art/build/build-art-module.sh
      packages/modules/ArtPrebuilt/update-art-module-prebuilts.py \
        --local-dist=out/dist --skip-cls
      m droid
Change-Id: I37c4e4b2164b65d7e41cf27ddf13cfa0632c59a7
3 files changed