Add gitlab ci/cd configuration file

image: "registry.gitlab.e.foundation:5000/e/apps/docker-android-apps-cicd:latest"

stages:

  - build

before_script:

  - export GRADLE_USER_HOME=$(pwd)/.gradle

  - chmod +x ./gradlew

  - ./gradlew clean

cache:

  key: ${CI_PROJECT_ID}

  paths:

    - .gradle/

build:

  stage: build

  script:

    - |

      ./gradlew build

      retval=$?

      if [$retval -ne 0]; then

        echo "error on building, exit code: "$retval

        exit $retval

      fi

  artifacts:

    paths:

      - app/build/outputs/apk