target-files: Support erofs_compress_hints

erofs_compress_hints files should be copied into target-files and then
sign_target_files_apks should use them from the target-files.

Bug: 357721652
Test: m target-files-package (with aosp/3204257)
Test: sign_target_files_apks <target_file> signed-target-files.zip
Change-Id: Id55000004ecb72ea8fec19bfbe144c9b4d3f06cb