releasetools: img_from_target_files uses zip2zip.

Test: Build the following targets and check the built image archive.
      bonito-userdebug (contains flashable images);
      cf_x86_phone-userdebug (contains super.img);
      aosp_arm64-eng (contains VerifiedBootParams.textproto)
Test: m -j otatools-package; Check that zip2zip is included; Use
      bin/img_from_target_files to generate image archive.
Change-Id: I9f28765bd702849f0df309faebd6aa3072920536