private void addGradleFiles(Project project) {
    Path projectPath = project.getProjectDir().toPath();

    // Add build.gradle
    skaffoldFilesOutput.addBuild(project.getBuildFile().toPath());

    // Add settings.gradle
    if (project.getGradle().getStartParameter().getSettingsFile() != null) {
      skaffoldFilesOutput.addBuild(
          project.getGradle().getStartParameter().getSettingsFile().toPath());
    } else if (Files.exists(projectPath.resolve(Settings.DEFAULT_SETTINGS_FILE))) {
      skaffoldFilesOutput.addBuild(projectPath.resolve(Settings.DEFAULT_SETTINGS_FILE));
    }

    // Add gradle.properties
    if (Files.exists(projectPath.resolve("gradle.properties"))) {
      skaffoldFilesOutput.addBuild(projectPath.resolve("gradle.properties"));
    }
  }
Adds the locations of a project's build.gradle, settings.gradle, and gradle.properties.

@param project the project
jib-gradle-plugin/src/main/java/com/google/cloud/tools/jib/gradle/skaffold/FilesTaskV2.java