[java] Fix some LocalVariableName checkstyle violations

No behavior change.

Bug: 542921651
Change-Id: I280f81bfb5a6b752283a5bdfb6400a2e23fb65b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/8219872
Owners-Override: Sam Maier <smaier@google.com>
Auto-Submit: Victor Vianna <victorvianna@google.com>
Reviewed-by: Sam Maier <smaier@google.com>
Commit-Queue: Sam Maier <smaier@google.com>
Commit-Queue: Victor Vianna <victorvianna@google.com>
Cr-Commit-Position: refs/heads/main@{#1676730}
NOKEYCHECK=True
GitOrigin-RevId: e203c0216659fc6882d1baa32f546c68efcdb2f7