[SPLTRP-1517]: Restore CodeQL configuration workflow

.github/workflows/codeql.yml

@@ -0,0 +1,69 @@
+name: "CodeQL"
+
+on:
+  push:
+    branches: [ main, develop ]
+  pull_request:
+    branches: [ main, develop ]
+    types: [ opened, synchronize, reopened, ready_for_review ]
+  schedule:
+    - cron: '0 6 * * 1' # Weekly Monday 06:00 UTC
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: ${{ github.event_name == 'pull_request' }}
+
+jobs:
+  analyze:
+    name: Analyze (Java/Kotlin)
+    if: github.event_name != 'pull_request' || !github.event.pull_request.draft
+    runs-on: ubuntu-latest
+    permissions:
+      security-events: write
+      contents: read
+      actions: read
+    env:
+      OER_APP_ID_RELEASE: ${{ secrets.OER_APP_ID_RELEASE }}
+      # Disable parallel and daemon to ensure CodeQL intercepts compiler correctly
+      GRADLE_OPTS: "-Dorg.gradle.jvmargs=-Xmx6g -Dorg.gradle.parallel=false -Dorg.gradle.daemon=false"
+    steps:
+      - uses: actions/checkout@v6
+
+      - name: Set up JDK 21
+        uses: actions/setup-java@v5
+        with:
+          java-version: '21'
+          distribution: 'temurin'
+
+      - name: Decode google-services.json
+        run: |
+          if [ -n "$GOOGLE_SERVICES_JSON_BASE64" ]; then
+            echo "$GOOGLE_SERVICES_JSON_BASE64" | base64 --decode > app/google-services.json
+          else
+            echo '{"project_info":{"project_number":"0","project_id":"placeholder","storage_bucket":"placeholder.appspot.com"},"client":[{"client_info":{"mobilesdk_app_id":"1:0:android:0","android_client_info":{"package_name":"es.pedrazamiguez.splittrip"}},"api_key":[{"current_key":"placeholder"}]}]}' > app/google-services.json
+          fi
+        env:
+          GOOGLE_SERVICES_JSON_BASE64: ${{ secrets.GOOGLE_SERVICES_JSON_BASE64 }}
+
+      - name: Setup Gradle
+        uses: gradle/actions/setup-gradle@v5
+        with:
+          cache-encryption-key: ${{ secrets.GRADLE_ENCRYPTION_KEY }}
+
+      - name: Grant execute permission for gradlew
+        run: chmod +x ./gradlew
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v4
+        with:
+          languages: java-kotlin
+          build-mode: manual
+
+      - name: Build for CodeQL
+        # We enforce no-build-cache and no-configuration-cache so that CodeQL can intercept a full build
+        run: ./gradlew clean assembleDebug --no-build-cache --no-configuration-cache
+
+      - name: Perform CodeQL Analysis
+        uses: github/codeql-action/analyze@v4
+        with:
+          category: "/language:java-kotlin"