Bug 40002: Add GitLab CI

Pin CI builds to runners with 32GB of RAM to avoid OOM conditions.

.gitlab-ci.yml

+variables:
+    DEBIAN_FRONTEND: noninteractive
+
+    ANDROID_CLI_TOOLS: "6609375"
+
+    ANDROID_CLI_TOOLS_DIGEST: "89f308315e041c93a37a79e0627c47f21d5c5edbe5e80ea8dc0aac8a649e0e92"
+    ANDROID_COMPILE_SDK: "28"
+    ANDROID_BUILD_TOOLS: "28.0.3"
+
+    MAVEN_REPOSITORIES: "${CI_PROJECT_DIR}/gradle_storage"
+    GRADLE_MAVEN_REPOSITORIES: "file://${MAVEN_REPOSITORIES}"
+
+
+default:
+    # See https://about.gitlab.com/blog/2018/10/24/setting-up-gitlab-ci-for-android-projects/
+    # https://github.com/docker-library/openjdk/blob/master/8/jdk/buster/Dockerfile
+    image: openjdk:8-jdk
+    tags:
+        - 32GB
+
+    before_script:
+        # Prepare our Debian environment.
+        - apt-get update -qq
+        - apt-get upgrade -qy
+
+        # Install needed packages from Debian.
+        - apt-get install -qy --fix-missing wget tar unzip lib32stdc++6 lib32z1 bzip2
+
+        #- ./taskcluster/scripts/toolchain/android-gradle-dependencies.sh
+
+        # Install the Android SDK Tools.
+        - wget --quiet --output-document=android-cli-tools.zip https://dl.google.com/android/repository/commandlinetools-linux-${ANDROID_CLI_TOOLS}_latest.zip
+        - echo "${ANDROID_CLI_TOOLS_DIGEST} android-cli-tools.zip" | sha256sum -c
+        - unzip -qd cmdline-tools android-cli-tools.zip
+        - echo y | cmdline-tools/tools/bin/sdkmanager --install "platforms;android-${ANDROID_COMPILE_SDK}" > /dev/null
+        - echo y | cmdline-tools/tools/bin/sdkmanager --install "platform-tools" > /dev/null
+        - echo y | cmdline-tools/tools/bin/sdkmanager --install "build-tools;${ANDROID_BUILD_TOOLS}" > /dev/null
+
+        # Install the Android NDK.
+        - echo y | cmdline-tools/tools/bin/sdkmanager ndk-bundle > /dev/null
+
+        # Accept all the licenses.
+        - set +o pipefail
+        - yes | cmdline-tools/tools/bin/sdkmanager --licenses > /dev/null
+        - set -o pipefail
+
+        # Create local.properties file.
+        - echo "sdk.dir=$PWD" > local.properties
+
+stages:
+    - build
+    - buildFenixProduction
+    - buildFennecBeta
+    - buildFennecProduction
+    - test
+
+buildDebug:
+    stage: build
+    script:
+        - ./gradlew clean app:assembleDebug --stacktrace
+
+    # Disable for now.
+    #artifacts:
+    #    paths:
+    #        - app/build/outputs/apk/geckoBeta/debug/*.apk
+    #    expire_in: 1 day
+
+testLight:
+    stage: test
+    script:
+        # from config/pre-push-recommended.sh
+        # `tee` into a log file because resulting output is larger than 4 MB
+        # (4 MB is max log size)
+        - ./gradlew ktlint detekt assembleDebug assembleDebugAndroidTest testDebug | tee testLight_gradle.log
+    artifacts:
+        paths:
+            - testLight_gradle.log
+        expire_in: 1 day
+        when: always
+
+#### Scheduled Jobs (build* stages run serially) ###
+
+buildFenixProduction:
+    stage: buildFenixProduction
+    only:
+        - schedules
+    script:
+        - ./gradlew clean app:assembleNightly --stacktrace
+
+buildFennecBeta:
+    stage: buildFennecBeta
+    only:
+        - schedules
+    script:
+        - ./gradlew clean app:assembleBeta --stacktrace
+
+buildFennecProduction:
+    stage: buildFennecProduction
+    only:
+        - schedules
+    script:
+        - ./gradlew clean app:assembleRelease --stacktrace
+
+testAll:
+    stage: test
+    only:
+        - schedules
+    script:
+        - ./gradlew clean test