sample: update WriteCommittedStream.java (#2047)

Fixes #2046 This change allows streamWriter to use BiqQuery Client passed to initialize method and not creating another copy of BigQuery client.

Author: OleksiyIvanov

samples/snippets/src/main/java/com/example/bigquerystorage/WriteCommittedStream.java

@@ -117,7 +117,8 @@ void initialize(TableName parentTable, BigQueryWriteClient client)
  // For more information about JsonStreamWriter, see:
  // https://googleapis.dev/java/google-cloud-bigquerystorage/latest/com/google/cloud/bigquery/storage/v1/JsonStreamWriter.html
  streamWriter =
- JsonStreamWriter.newBuilder(writeStream.getName(), writeStream.getTableSchema()).build();
+ JsonStreamWriter.newBuilder(writeStream.getName(), writeStream.getTableSchema(), client)
+ .build();
  }
 
  public void append(JSONArray data, long offset)