Generate apex_info.pb,care_map.pb,vbmeta_digest.txt in target_files

These files are implicit outputs created by `add_img_to_target_files`

Bug: 399788207
Test: Built soong and make target_files.zip
Test: apex_info.pb is bit-identical
Test: care_map.pb is _not_ bit-identical (likely because of notice
files)
Test: vbmeta_digest.txt is _not_ bit-identical (vbmeta.img is not
bit-identical)

Change-Id: I1bfc1a738895dc23fef41e0e6aa08d42295b0bfe