Firebase Emulator on Bitbucket Pipeline

I'm trying to run Firebase Emulator on Bitbucket Pipeline. It fails because "java is not installed".

How can I "install java" on a Bitbucket Pipeline. Or is there another way to get it to work?

My step currently looks like this:

- step: &test-rules
        name: 'Test Firestore Rules (DEV)'
        image: node:16.13.2
        script:
          - npm ci --prefix firebase-test
          - npm install -g firebase-tools
          - npm run test --prefix firebase-test

npm run test runs this script:

firebase emulators:exec --only firestore "mocha --exit"