Add ErrorProne check to assert use of android.support.annotation.Nullable

Adds an android ErrorProne check to give a compiler error
when using javax Nullable instead of android Nullable.
See bug for motivation.

Bug: 771683
Change-Id: I6384fa515405159e3fa894303022cad8bfc389b9
Reviewed-on: https://chromium-review.googlesource.com/c/1363677
Commit-Queue: Aiden Benner <abenner@google.com>
Reviewed-by: agrieve <agrieve@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#614445}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: f6f6371df0c9151ab37afb7ec65f15300a764edd
2 files changed