build: set the export goma auth fallback flag for the control process (#30317)

Co-authored-by: Samuel Attard <[email protected]>

.circleci/config.yml

@@ -342,6 +342,7 @@ step-setup-goma-for-build: &step-setup-goma-for-build
       npm install
       mkdir third_party
       node -e "require('./src/utils/goma.js').downloadAndPrepare({ gomaOneForAll: true })"
+      export GOMA_FALLBACK_ON_AUTH_FAILURE=true
       third_party/goma/goma_ctl.py ensure_start
       echo 'export GN_GOMA_FILE='`node -e "console.log(require('./src/utils/goma.js').gnFilePath)"` >> $BASH_ENV
       echo 'export LOCAL_GOMA_DIR='`node -e "console.log(require('./src/utils/goma.js').dir)"` >> $BASH_ENV