fix: add per-service api_version to gapic_metadata

Author: noahdietz

gapic-generator-java/pom.xml

@@ -14,7 +14,7 @@
     <clirr.skip>true</clirr.skip>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
     <!-- Should be in sync with repositories.bzl -->
-    <googleapis.commit>44d6bef0ca6db8bba3fb324c8186e694bcc4829c</googleapis.commit>
+    <googleapis.commit>9fcfbea0aa5b50fa22e190faceb073d74504172b</googleapis.commit>
     <maven.compiler.source>1.8</maven.compiler.source>
     <maven.compiler.target>1.8</maven.compiler.target>
   </properties>

gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/common/AbstractServiceClientClassComposer.java

@@ -1898,12 +1898,17 @@ private static void updateGapicMetadata(
       serviceClientProtoBuilder.putRpcs(rpcName, methodList);
     }
 
+    GapicMetadata.ServiceForTransport.Builder grpcServiceClient = 
+        GapicMetadata.ServiceForTransport.newBuilder()
+            .putClients("grpc", serviceClientProtoBuilder.build());
+
+    if (service.hasApiVersion()) {
+        grpcServiceClient.setApiVersion(service.apiVersion());
+    }
+
     metadataBuilder =
         metadataBuilder.putServices(
-            service.name(),
-            GapicMetadata.ServiceForTransport.newBuilder()
-                .putClients("grpc", serviceClientProtoBuilder.build())
-                .build());
+            service.name(),grpcServiceClient.build());
     context.updateGapicMetadata(metadataBuilder.build());
   }
 }