[GHA] GCP Backup upload working

Author: BoykoAlex

.github/workflows/backup-eclipse-releases-to-gcp.yml

@@ -28,6 +28,7 @@ jobs:
       - name: Authenticate to GCP
         run: |
           json='${{ secrets.CDN_SPRING_IO_BACKUP_GCP_BUCKET_JSON }}'
+          json=${json//\"/\\\"}
           echo -e "$json" > ./gcp.json
           gcloud auth activate-service-account --key-file=./gcp.json
           rm -f gcp.json