Update GitHub Actions workflow to generate FDC SDKs

[thatfiredev]

The build in #1671 is failing because FDC needs its SDK to be generated from the Firebase CLI.

Here are some options (that I can think of) to fix the CI pipeline:

1. (preferred) Add the Firebase CLI to our CI pipeline so that those SDKs can be generated
2. Pre-generate those, commit to a separate directory and just copy them to the appropriate directory during the CI workflow.
3. Generate mocks/fakes of those files that are only used in CI for the build to pass.