Allow configuration to be serialized

Author: damccorm

sdks/java/io/amazon-web-services2/src/main/java/org/apache/beam/sdk/io/aws2/kinesis/KinesisTransformRegistrar.java

@@ -120,7 +120,7 @@ public PTransform<PCollection<byte[]>, KinesisIO.Write.Result> buildExternal(
               .withClientConfiguration(
                   ClientConfiguration.builder()
                       .credentialsProvider(provider)
-                      .region(Regions.fromName(configuration.region))
+                      .region(Region.of(configuration.region))
                       .endpoint(endpoint)
                       .build())
               .withPartitioner(p -> configuration.partitionKey)
@@ -230,7 +230,7 @@ public PTransform<PBegin, PCollection<byte[]>> buildExternal(
               .withClientConfiguration(
                   ClientConfiguration.builder()
                       .credentialsProvider(provider)
-                      .region(Regions.fromName(configuration.region))
+                      .region(Region.of(configuration.region))
                       .endpoint(endpoint)
                       .build());