chore: update gapic-generator-java version to 2.1.0 (#990)

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PiperOrigin-RevId: 391407209
Source-Link: googleapis/googleapis@e1738ee

Author: yoshi-automation

google-cloud-bigquerydatatransfer/src/main/java/com/google/cloud/bigquery/datatransfer/v1/stub/DataTransferServiceStubSettings.java

@@ -504,7 +504,9 @@ public static List<String> getDefaultServiceScopes() {
 
   /** Returns a builder for the default credentials for this service. */
   public static GoogleCredentialsProvider.Builder defaultCredentialsProviderBuilder() {
-    return GoogleCredentialsProvider.newBuilder().setScopesToApply(DEFAULT_SERVICE_SCOPES);
+    return GoogleCredentialsProvider.newBuilder()
+        .setScopesToApply(DEFAULT_SERVICE_SCOPES)
+        .setUseJwtAccessWithScope(true);
   }
 
   /** Returns a builder for the default ChannelProvider for this service. */

synth.metadata

@@ -11,15 +11,15 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/java-bigquerydatatransfer.git",
-        "sha": "862432f29fcf300bdee0d0c1b119333c9bd5a1f1"
+        "sha": "e8411717edf260e055bf44ce62bb870fe2ce46ad"
       }
     },
     {
       "git": {
         "name": "googleapis",
         "remote": "https://github.com/googleapis/googleapis.git",
-        "sha": "d9eaf41de44d953458b18712a3f240bb4c564e48",
-        "internalRef": "388535346"
+        "sha": "e1738ee972b49fd0c4d4718b035444495142b781",
+        "internalRef": "391407209"
       }
     },
     {