[BOOK-202] feat: CI 내에 Generate google-services.json step 추가

Author: easyhooon

.github/workflows/android-ci.yml

@@ -39,6 +39,9 @@ jobs:
                 run: |
                     echo '${{ secrets.LOCAL_PROPERTIES }}' >> ./local.properties
 
+            -   name: Generate google-services.json
+                run: echo '${{ secrets.GOOGLE_SERVICES }}' | base64 -d > ./app/google-services.json
+
             -   name: Code style checks
                 run: |
                     ./gradlew ktlintCheck detekt