Run integration test on CI

[littleGnAl]

I've found that the arm64 base Android emulator successfully runs integration tests. However, it cannot be executed on GitHub Actions currently (see this issue). Additionally, the iOS simulator cannot run in release mode, which blocks us from running integration tests on CI.

We likely need to use Firebase Test Lab, but there's no free plan for open-source projects. We're still looking for a way to manage this.