THRIFT-5632: [java][lib] fix pmd main for java

[jimexist]

• Did you create an Apache Jira ticket? (not required for trivial changes)
• If a ticket exists: Does your pull request title follow the pattern "THRIFT-NNNN: describe my issue"?
• Did you squash your changes to a single commit? (not required, but preferred)
• Did you do your best to avoid breaking changes? If one was needed, did you label the Jira ticket with "Breaking-Change"?
• If your change does not involve any code, include [skip ci] anywhere in the commit message to free up build resources.

[jimexist]

After the fix:

thrift/lib/java on  master [$?] via △ v3.23.3 via ☕ v18.0.2.1 took 8s
❯ ./gradlew :pmdMain

> Task :compileJava
Note: Some input files use unchecked or unsafe operations.
Note: Recompile with -Xlint:unchecked for details.

BUILD SUCCESSFUL in 4s
3 actionable tasks: 2 executed, 1 up-to-date