我在GitHub上有一个项目，我想设置CI作业来构建docker映像并推送到AWS ECR。我的要求是-

1. 一个ci文件（我已创建.github/workflows/aws.yml）
2. CI作业必须仅在推送到master和sandbox分支上触发
3. 如果推送到沙盒分支，则应将Docker映像推送到ECR1
4. 如果将其推送到master分支，则应将docker image推送到ECR2

到目前为止，我已经制作了以下CI文件

.github / workflows / aws.yml -

  name: CI

  on:
    pull_request:
      branches:
      - master
      - sandbox
    push:
      branches:
      - master
      - sandbox

  env:
    AWS_REPOSITORY_URL_MASTER: ${{ secrets.AWS_REPOSITORY_URL_MASTER }}
    AWS_REPOSITORY_URL_SANDBOX: ${{ secrets.AWS_REPOSITORY_URL_SANDBOX }}
    AWS_accESS_KEY_ID: ${{ secrets.AWS_accESS_KEY_ID }}
    AWS_SECRET_accESS_KEY: ${{ secrets.AWS_SECRET_accESS_KEY }}

  jobs:
    build-and-push:
      name: Build and push image to AWS ECR master
      runs-on: ubuntu-latest
      steps:

      - name: Checkout
        uses: actions/checkout@v2

      - name: Setup ECR
        run: $( aws ecr get-login --no-include-email --region ap-south-1)

      - name: Build and tag the image
        run: docker build -t $AWS_REPOSITORY_URL_MASTER .

      - name: Push
        run: docker push $AWS_REPOSITORY_URL_MASTER
    build-and-push-sandbox:
      name: Build and push image to AWS ECR master
      runs-on: ubuntu-latest
      steps:

      - name: Checkout
        uses: actions/checkout@v2

      - name: Setup ECR
        run: $( aws ecr get-login --no-include-email --region ap-south-1)

      - name: Build and tag the image
        run: docker build -t $AWS_REPOSITORY_URL_SANDBOX .

      - name: Push
        run: docker push $AWS_REPOSITORY_URL_SANDBOX

该脚本将如何区分何时运行build-and-push-master（在主分支推送时触发）和build-and-push-sandbox（在沙箱分支推送时触发）？