fix indexer build pipelines

Author: dantelmomsft

.github/workflows/app-ci.yaml

@@ -50,6 +50,12 @@ jobs:
           npm run build
           mkdir -p ../backend/src/main/resources/static
           cp -r ./build/* ../backend/src/main/resources/static
+      
+      - name: Verify Indexer project
+        run: |
+          echo "Testing indexer project."
+          cd ./app/indexer
+          ./mvnw test
 
       - name: Build Spring Boot App
         run: |