chore: modify readme's transport support description

.repo-metadata.json

@@ -5,7 +5,7 @@
   "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.",
   "client_documentation": "https://cloud.google.com/java/docs/reference/google-cloud-storage/latest/history",
   "release_level": "stable",
-  "transport": "grpc",
+  "transport": "http",
   "language": "java",
   "repo": "googleapis/java-storage",
   "repo_short": "java-storage",

README.md

@@ -414,7 +414,7 @@ To get help, follow the instructions in the [shared Troubleshooting document][tr
 
 ## Transport
 
-Cloud Storage uses gRPC for the transport layer.
+Cloud Storage uses HTTP/JSON for the transport layer.
 
 ## Supported Java Versions
 

generation_config.yaml

@@ -20,6 +20,7 @@ libraries:
     extra_versioned_modules: gapic-google-cloud-storage-v2
     excluded_poms: google-cloud-storage-bom,google-cloud-storage
     recommended_package: com.google.cloud.storage
+    transport: rest
     GAPICs:
       - proto_path: google/storage/v2
       - proto_path: google/storage/control/v2