This CL adds the building rules for the following tools:
- add_img_to_target_files
- check_ota_package_signature
- check_target_files_signatures
- img_from_target_files
- merge_target_files
- ota_package_parser
- sign_apex
- sign_target_files_apks
- validate_target_files
Bug: 63866463
Test: mmma -j build/make/tools/releasetools
Test: Run each tool above to ensure there's no missing dependency (in
the exercised code path).
Change-Id: Ide5b9775939ed02c822109cbcf4224000d5472df