Add Google Cloud dependencies to UI backend service

Author: jbvaningen

services/ui_backend_service/requirements.txt

@@ -9,4 +9,5 @@ aiohttp_cors==0.7.0
 metaflow>=2.9.6
 click==8.0.3
 azure-storage-blob==12.13.1
-azure-identity==1.10.0
+azure-identity==1.10.0
+google-cloud-storage~=2.10.0