chore: run fmt command on java-dataplex (#12317)

This PR fixes lint issues with java-dataplex that are blocking [spanner
PR](#12293)

The [lint check on spanner
PR](https://github.com/googleapis/google-cloud-java/actions/runs/23763214864/job/69235942554?pr=12293)is
failing due to:

```
Error:  Failed to execute goal com.spotify.fmt:fmt-maven-plugin:2.25:check (default-cli) on project grpc-google-cloud-dataplex-v1: Found 1 non-complying files, failing build -> [Help 1]
```

Author: ldetmer

java-dataplex/grpc-google-cloud-dataplex-v1/src/main/java/com/google/cloud/dataplex/v1/ContentServiceGrpc.java

@@ -15,7 +15,6 @@
  */
 package com.google.cloud.dataplex.v1;
 
-
 /**
  *
  *