The genrules in app module's BUILD file are necessary only for building Oppia Android in both Gradle and Bazel. Similarly, the custom macro in the model module (format_import_proto_library.bzl) will need to be removed once Gradle is out of the picture. For both genrules, removing them will require changing some import statements (Ex. import org.oppia.app.R -> import org.oppia.app.vm.R).