Caching buildah images (base + created) using github actions/cache

Question

I want to cache the buildah images so that they are not pulled every time using github actions/cache. Can you please help me understand what layers should be cached. I started with ~/var/lib/containers and /var/lib/containers but that did not help

jobs:
  # This workflow contains a single job called "greet"
  build:
    # The type of runner that the job will run on
    runs-on: ubuntu-latest
    steps:
    - uses: actions/checkout@master
    - name: Set up JDK 1.8
      uses: actions/setup-java@v1
      with:
        java-version: 1.8
    - name: Install oc tool
      run: mkdir /tmp/s2i/ && cd /tmp/s2i/ && curl -s https://api.github.com/repos/openshift/source-to-image/releases/latest | grep browser_download_url | grep linux-amd64 | cut -d '"' -f 4 | wget -qi - && tar xvf source-to-image*.gz && sudo mv s2i /usr/local/bin && rm -rf /tmp/s2i/
    - name: Login to quay.io using Buildah
      run: buildah login -u ${{ secrets.QUAY_USERNAME }} -p ${{ secrets.QUAY_PASSWORD }} quay.io
    - name: Cache local Maven repository & buildah containers
      uses: actions/cache@v2
      with:
        path: |
          ~/.m2/repository
        key: ${{ runner.os }}-maven-buildah-${{ hashFiles('**/pom.xml') }}
        restore-keys: |
          ${{ runner.os }}-maven-buildah-
    - name: Build with Maven
      run: pwd && mvn -B clean install -DskipTests -f ./vertx-starter/pom.xml
    - name: Create the Dockerfile
      run: printf "FROM openjdk:8-slim\nARG JAR_FILE=target/*.jar\nRUN mkdir -p /deployments\nCOPY \${JAR_FILE} /deployments/app.jar\nRUN chown -R 1001:0 /deployments && chmod -R 0755 /deployments\nEXPOSE 8080 8443\n USER 1001\nENTRYPOINT [\"java\",\"-jar\",\"/deployments/app.jar\"]" > Dockerfile && cat Dockerfile
    - name: Create image using buildah
      run: buildah bud --layers --log-level debug --build-arg JAR_FILE="vertx-starter/target/app.jar" -t quay.io/himanshumps/vertx_demo .