Generates the care_map.txt in protobuf format

Call the host binary care_map_generator to generate the care_map in
protobuf format. The parsing part of proto messages has already been
supported in the update_verifier.

Bug: 77867897
Test: unittests pass; run add_image_to_target_files
Change-Id: I40d3184b4b5c48a6dd55203afc84cca73d5765e9