Fastfile_sign_zipalign_start.rb

desc "Build a signed release APK & deploy to slack"
  lane :slack_apk_build do
    gradle(
      task: "assemble",
      build_type: "Release",
      print_command: false,
      properties: {
        "android.injected.signing.store.file" => "keystore.jks",
        "android.injected.signing.store.password" => "store_password",
        "android.injected.signing.key.alias" => "key_alias",
        "android.injected.signing.key.password" => "key_password",
      }
    )
end