Add a CI job to build Android demo app (#2392)

Summary:
This PR installs Android NDK, SDK, JDK17 and build the Android demo app on CI to make sure that the build works correctly.

For the context, I follow the instructions on https://github.com/pytorch/executorch/tree/main/examples/demo-apps/android/ExecuTorchDemo and get a linker error w.r.t `extension_data_loader`. This should have been caught on CI if there is a CI job to build the demo app.

### Testing

https://github.com/pytorch/executorch/actions/runs/8291075650/job/22690178957?pr=2392

Pull Request resolved: https://github.com/pytorch/executorch/pull/2392

Reviewed By: kirklandsign

Differential Revision: D54934888

Pulled By: huydhn

fbshipit-source-id: ace675c4bbf81c22c9586d59d4e8b1d481b63b39