Add e2e test for rolling back build mode

.github/workflows/__build-mode-rollback.yml

@@ -0,0 +1,89 @@
+# Warning: This file is generated automatically, and should not be modified.
+# Instead, please modify the template in the pr-checks directory and run:
+#     (cd pr-checks; pip install ruamel.yaml@0.17.31 && python3 sync.py)
+# to regenerate this file.
+
+name: PR Check - Build mode rollback
+env:
+  GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+  GO111MODULE: auto
+  CODEQL_EXTRACTOR_JAVA_AGENT_DISABLE_KOTLIN: 'true'
+on:
+  push:
+    branches:
+    - main
+    - releases/v*
+  pull_request:
+    types:
+    - opened
+    - synchronize
+    - reopened
+    - ready_for_review
+  workflow_dispatch: {}
+jobs:
+  build-mode-rollback:
+    strategy:
+      matrix:
+        include:
+        - os: ubuntu-latest
+          version: nightly-latest
+    name: Build mode rollback
+    permissions:
+      contents: read
+      security-events: write
+    timeout-minutes: 45
+    runs-on: ${{ matrix.os }}
+    steps:
+    - name: Setup Python on MacOS
+      uses: actions/setup-python@v5
+      if: >-
+        matrix.os == 'macos-latest' && (
+
+        matrix.version == 'stable-20221211' ||
+
+        matrix.version == 'stable-20230418' ||
+
+        matrix.version == 'stable-v2.13.5' ||
+
+        matrix.version == 'stable-v2.14.6')
+      with:
+        python-version: '3.11'
+    - name: Check out repository
+      uses: actions/checkout@v4
+    - name: Prepare test
+      id: prepare-test
+      uses: ./.github/actions/prepare-test
+      with:
+        version: ${{ matrix.version }}
+        use-all-platform-bundle: 'false'
+    - name: Set environment variable for Swift enablement
+      if: runner.os != 'Windows' && matrix.version == '20221211'
+      shell: bash
+      run: echo "CODEQL_ENABLE_EXPERIMENTAL_FEATURES_SWIFT=true" >> $GITHUB_ENV
+    - name: Set up Java test repo configuration
+      run: |
+        mv * .github ../action/tests/multi-language-repo/
+        mv ../action/tests/multi-language-repo/.github/workflows .github
+        mv ../action/tests/java-repo/* .
+
+    - uses: ./../action/init
+      id: init
+      with:
+        build-mode: none
+        db-location: ${{ runner.temp }}/customDbLocation
+        languages: java
+        tools: ${{ steps.prepare-test.outputs.tools-url }}
+
+    - name: Validate database build mode
+      run: |
+        metadata_path="$RUNNER_TEMP/customDbLocation/java/codeql-database.yml"
+        build_mode=$(yq eval '.buildMode' "$metadata_path")
+        if [[ "$build_mode" != "autobuild" ]]; then
+          echo "Expected build mode to be 'autobuild' but was $build_mode"
+          exit 1
+        fi
+
+    - uses: ./../action/analyze
+    env:
+      CODEQL_ACTION_DISABLE_JAVA_BUILDLESS: true
+      CODEQL_ACTION_TEST_MODE: true

pr-checks/checks/build-mode-rollback.yml

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+name: "Build mode rollback"
+description: "The build mode is rolled back from none to autobuild when the relevant feature flag is enabled."
+operatingSystems: ["ubuntu"]
+versions: ["nightly-latest"]
+env:
+  CODEQL_ACTION_DISABLE_JAVA_BUILDLESS: true
+steps:
+  - name: Set up Java test repo configuration
+    run: |
+      mv * .github ../action/tests/multi-language-repo/
+      mv ../action/tests/multi-language-repo/.github/workflows .github
+      mv ../action/tests/java-repo/* .
+
+  - uses: ./../action/init
+    id: init
+    with:
+      build-mode: none
+      db-location: "${{ runner.temp }}/customDbLocation"
+      languages: java
+      tools: ${{ steps.prepare-test.outputs.tools-url }}
+
+  - name: Validate database build mode
+    run: |
+      metadata_path="$RUNNER_TEMP/customDbLocation/java/codeql-database.yml"
+      build_mode=$(yq eval '.buildMode' "$metadata_path")
+      if [[ "$build_mode" != "autobuild" ]]; then
+        echo "Expected build mode to be 'autobuild' but was $build_mode"
+        exit 1
+      fi
+
+  - uses: ./../action/analyze