Merge "Fix errorprone warnings that should be errors" am: ea4d7833fb am: 2eca2e750b am: 6b5ac19aed

Original change: https://android-review.googlesource.com/c/platform/external/antlr/+/2256447

Change-Id: Ib3f948ae7cb6c7a671a7ab8db4f727179048af6a
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>