chore: remove obsolete sample code (#1985)

* chore: remove unused sample file * 🦉 Updates from OwlBot post-processor See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md --------- Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: yirutang

README.md

@@ -108,7 +108,6 @@ Samples are in the [`samples/`](https://github.com/googleapis/java-bigquerystora
 
 | Sample | Source Code | Try it |
 | --------------------------- | --------------------------------- | ------ |
-| Bq To Bq Storage Schema Converter | [source code](https://github.com/googleapis/java-bigquerystorage/blob/main/samples/snippets/src/main/java/com/example/bigquerystorage/BqToBqStorageSchemaConverter.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquerystorage&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquerystorage/BqToBqStorageSchemaConverter.java) |
 | Parallel Write Committed Stream | [source code](https://github.com/googleapis/java-bigquerystorage/blob/main/samples/snippets/src/main/java/com/example/bigquerystorage/ParallelWriteCommittedStream.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquerystorage&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquerystorage/ParallelWriteCommittedStream.java) |
 | Storage Arrow Sample | [source code](https://github.com/googleapis/java-bigquerystorage/blob/main/samples/snippets/src/main/java/com/example/bigquerystorage/StorageArrowSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquerystorage&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquerystorage/StorageArrowSample.java) |
 | Storage Sample | [source code](https://github.com/googleapis/java-bigquerystorage/blob/main/samples/snippets/src/main/java/com/example/bigquerystorage/StorageSample.java) | [![Open in Cloud Shell][shell_img]](https://console.cloud.google.com/cloudshell/open?git_repo=https://github.com/googleapis/java-bigquerystorage&page=editor&open_in_editor=samples/snippets/src/main/java/com/example/bigquerystorage/StorageSample.java) |