fix: Add back the accidentally removed background executor provider (#1899)

* feat: Split writer into connection worker and wrapper, this is a
prerequisite for multiplexing client

* feat: add connection worker pool skeleton, used for multiplexing client

* feat: add Load api for connection worker for multiplexing client

* feat: add multiplexing support to connection worker. We will treat every
new stream name as a switch of destinationt

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* feat: port the multiplexing client core algorithm and basic tests
also fixed a tiny bug inside fake bigquery write impl for getting thre
response from offset

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* feat: wire multiplexing connection pool to stream writer

* feat: some fixes for multiplexing client

* feat: fix some todos, and reject the mixed behavior of passed in client or not

* feat: fix the bug that we may peek into the write_stream field but it's
possible the proto schema does not contain this field

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* feat: fix the bug that we may peek into the write_stream field but it's
possible the proto schema does not contain this field

* feat: add getInflightWaitSeconds implementation

* feat: Add schema comparision in connection loop to ensure schema update for
the same stream name can be notified

* 🦉 Updates from OwlBot post-processor

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* feat: add schema update support to multiplexing

* fix: fix windows build bug: windows Instant resolution is different with
linux

* fix: fix another failing tests for windows build

* fix: fix another test failure for Windows build

* feat: Change new thread for each retry to be a thread pool to avoid
create/tear down too much threads if lots of retries happens

* 🦉 Updates from OwlBot post-processor

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* fix: add back the background executor provider that's accidentally
removed

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Author: GaoleMeng

google-cloud-bigquerystorage/src/main/java/com/google/cloud/bigquery/storage/v1/StreamWriter.java

@@ -279,6 +279,7 @@ private BigQueryWriteClient getBigQueryWriteClient(Builder builder) throws IOExc
           BigQueryWriteSettings.newBuilder()
               .setCredentialsProvider(builder.credentialsProvider)
               .setTransportChannelProvider(builder.channelProvider)
+              .setBackgroundExecutorProvider(builder.executorProvider)
               .setEndpoint(builder.endpoint)
               .build();
       testOnlyClientCreatedTimes++;