Add missed param to doc.

Author: Bingqin Zhou

kcbq-connector/src/main/java/com/wepay/kafka/connect/bigquery/BigQuerySinkTask.java

@@ -110,6 +110,7 @@ public BigQuerySinkTask() {
    * @param testBigQuery {@link BigQuery} to use for testing (likely a mock)
    * @param schemaRetriever {@link SchemaRetriever} to use for testing (likely a mock)
    * @param testGcs {@link Storage} to use for testing (likely a mock)
+   * @param testSchemaManager {@link SchemaManager} to use for testing (likely a mock)
    * @see BigQuerySinkTask#BigQuerySinkTask()
    */
   public BigQuerySinkTask(BigQuery testBigQuery, SchemaRetriever schemaRetriever, Storage testGcs, SchemaManager testSchemaManager) {