Fix MaxIndex in test-gap-resolver.cc so that the above check doesn't
fire.

Change-Id: I6588800281d797f3f8b33ced4c1b03315196fe44
Reviewed-on: https://chromium-review.googlesource.com/618809Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Albert Mingkun Yang <albertnetymk@google.com>
Cr-Commit-Position: refs/heads/master@{#47421}