Context:
The SyncCreateSetCredentialsProvider sample already exists: https://github.com/googleapis/google-cloud-java/blob/56c9a8a29c1d04baed958cc028918eea5995aa17/java-tpu/samples/snippets/generated/com/google/cloud/tpu/v2/tpu/create/SyncCreateSetCredentialsProvider.java

and it properly showcases setting the credentials. The SyncCreateSetCredentialsProvider1 sample should be named something that reflects that it is using httpjson.

This generator's logic seems to set the wrong region tag name:
https://github.com/googleapis/gapic-generator-java/blob/8ef747b244c9bed128252cb6913d954ae7270251/gapic-generator-java/src/main/java/com/google/api/generator/gapic/composer/samplecode/ServiceClientHeaderSampleComposer.java#L345

The logic may have been mistakenly copied over. This is creating samples with SyncCreateSetCredentialsProvider1 as the filename instead of something like ComposeTranport or UseHttpJsonTransport.

https://github.com/googleapis/google-cloud-java/blob/56c9a8a29c1d04baed958cc028918eea5995aa17/java-tpu/samples/snippets/generated/com/google/cloud/tpu/v2/tpu/create/SyncCreateSetCredentialsProvider1.java#L23