Repository: flutter
Issue: How to use *both* 32-bit (arm) and 64-bit (arm64) to package an APK/AAB file with custom flutter engine?
Labels: c: new feature,platform-android,tool,P3,team-android,triaged-android

<!-- Thank you for using Flutter!

     If you are looking for support, please check out our documentation
     or consider asking a question on Stack Overflow:
      * https://flutter.dev/
      * https://api.flutter.dev/
      * https://stackoverflow.com/questions/tagged/flutter?sort=frequent

     If you have found a bug or if our documentation doesn't have an answer
     to what you're looking for, then fill out the template below. Please read
     our guide to filing a bug first: https://flutter.dev/docs/resources/bug-reports
-->

Hi thanks for the wonderful lib! I wonder how to use *both* 32-bit (arm) and 64-bit (arm64) to package an APK/AAB file with custom flutter engine?

According to https://github.com/flutter/flutter/wiki/The-flutter-tool, I should use `--local-engine-src-path /path/to/engine/src --local-engine=android_debug_unopt` to specify I want android. Since I want to build a release mode apk/aab, I guess should use `--local-engine=android_release`. However the problem is that, I also want 64bit android which is `android_release_arm64` instead of `android_release`, but seems that I can only specify one local engine instead of two.

More details: I hope to build a apk/aab file, which contains *two* `libflutter.so`, one for 32bit arm, one for 64bit arm.

## Steps to Reproduce

<!-- Please include full steps to reproduce so that we can reproduce the problem. -->

1. Execute `flutter run` on the code sample <!-- (see "Code sample" section below) -->
2. ... <!-- describe steps to demonstrate bug -->
3. ... <!-- for example "Tap on X and see a crash" -->

**Expected results:** <!-- what did you want to see? -->

**Actual results:** <!-- what did you see? -->

<details>
<summary>Code sample</summary>

<!--
      Please create a minimal reproducible sample that shows the problem
      and attach it below between the lines with the backticks.

      To create it you can use `flutter create bug` command and update the `main.dart` file.

      Alternatively, you can use https://dartpad.dev/
      which is capable of creating and running small Flutter apps.

      Without this we will unlikely be able to progress on the issue, and because of that
      we regretfully will have to close it.
-->

```dart
```

</details>

<details>
  <summary>Logs</summary>

<!--
      Run your application with `flutter run --verbose` and attach all the
      log output below between the lines with the backticks. If there is an
      exception, please see if the error message includes enough information
      to explain how to solve the issue.
-->

```
```

<!--
     Run `flutter analyze` and attach any output of that command below.
     If there are any analysis errors, try resolving them before filing this issue.
-->

```
```

<!-- Finally, paste the output of running `flutter doctor -v` here. -->

```
```

</details>


<!--
      Consider also attaching screenshots and/or videos to better
      illustrate the issue.

      You can upload them directly on GitHub.
      Beware that video file size is limited to 10MB.
-->