Fix errorprone warnings that should be errors am: bbab10c64b

Original change: https://android-review.googlesource.com/c/platform/external/apache-commons-math/+/2254820

Change-Id: I0b1c1db28931229ae62eebfb2dc5d2e0f73ddfe4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>