fix environment variables

Author: dashpole

samples/instrumentation-quickstart/docker-compose.cloudbuild.yaml

@@ -22,3 +22,8 @@ networks:
   default:
     name: cloudbuild
     external: true
+services:
+  otelcol:
+    environment:
+      - GOOGLE_CLOUD_PROJECT=${_GOOGLE_CLOUD_PROJECT}
+      - GOOGLE_CLOUD_QUOTA_PROJECT=${_GOOGLE_CLOUD_PROJECT}