Fix errorprone warnings that should be errors am: 083e4f4123 am: d76e8fd2e9 am: 953e117c85

Original change: https://android-review.googlesource.com/c/platform/external/mobile-data-download/+/2256435

Change-Id: Id985d2eecc6cd377c1ae9214ac5d2cb7c786389f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>