[misc] add back environment variables for gcs buckets

services/filestore/buildscript.txt

@@ -2,7 +2,7 @@ filestore
 --data-dirs=uploads,user_files,template_files
 --dependencies=s3,gcs
 --docker-repos=gcr.io/overleaf-ops
---env-add=ENABLE_CONVERSIONS="true",USE_PROM_METRICS="true",AWS_S3_USER_FILES_BUCKET_NAME=fake_user_files,AWS_S3_TEMPLATE_FILES_BUCKET_NAME=fake_template_files,AWS_S3_PUBLIC_FILES_BUCKET_NAME=fake_public_files
+--env-add=ENABLE_CONVERSIONS="true",USE_PROM_METRICS="true",AWS_S3_USER_FILES_BUCKET_NAME=fake_user_files,AWS_S3_TEMPLATE_FILES_BUCKET_NAME=fake_template_files,AWS_S3_PUBLIC_FILES_BUCKET_NAME=fake_public_files,GCS_USER_FILES_BUCKET_NAME=fake_userfiles,GCS_TEMPLATE_FILES_BUCKET_NAME=fake_templatefiles,GCS_PUBLIC_FILES_BUCKET_NAME=fake_publicfiles
 --env-pass-through=
 --node-version=12.18.0
 --public-repo=True

services/filestore/docker-compose.ci.yml

@@ -38,6 +38,9 @@ services:
       AWS_S3_USER_FILES_BUCKET_NAME: fake_user_files
       AWS_S3_TEMPLATE_FILES_BUCKET_NAME: fake_template_files
       AWS_S3_PUBLIC_FILES_BUCKET_NAME: fake_public_files
+      GCS_USER_FILES_BUCKET_NAME: fake_userfiles
+      GCS_TEMPLATE_FILES_BUCKET_NAME: fake_templatefiles
+      GCS_PUBLIC_FILES_BUCKET_NAME: fake_publicfiles
     depends_on:
       s3:
         condition: service_healthy

services/filestore/docker-compose.yml

@@ -48,6 +48,9 @@ services:
       AWS_S3_USER_FILES_BUCKET_NAME: fake_user_files
       AWS_S3_TEMPLATE_FILES_BUCKET_NAME: fake_template_files
       AWS_S3_PUBLIC_FILES_BUCKET_NAME: fake_public_files
+      GCS_USER_FILES_BUCKET_NAME: fake_userfiles
+      GCS_TEMPLATE_FILES_BUCKET_NAME: fake_templatefiles
+      GCS_PUBLIC_FILES_BUCKET_NAME: fake_publicfiles
     user: node
     depends_on:
       s3: