Fix errorprone warnings that should be errors am: 3805153287

Original change: https://android-review.googlesource.com/c/platform/external/oj-libjdwp/+/2255383

Change-Id: I522d5a20b7ac91f765893abaf5ee635ac0ceee02
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>