chore: surround string with special characters with quotes in generat…

…ion_config (#2618)

generation_config.yaml

@@ -6,7 +6,7 @@ libraries:
     name_pretty: Cloud Storage
     product_documentation: https://cloud.google.com/storage
     client_documentation: https://cloud.google.com/java/docs/reference/google-cloud-storage/latest/history
-    api_description: is a durable and highly available object storage service. Google Cloud Storage is almost infinitely scalable and guarantees consistency: when a write succeeds, the latest copy of the object will be returned to any GET, globally.
+    api_description: 'is a durable and highly available object storage service. Google Cloud Storage is almost infinitely scalable and guarantees consistency: when a write succeeds, the latest copy of the object will be returned to any GET, globally.'
     issue_tracker: https://issuetracker.google.com/savedsearches/559782
     release_level: stable
     language: java