Extend ServiceWorker.InternalsPageAccessed expiration date

We still want to see the number.

Bug: 1125764
Change-Id: I711c13c386f9beefcf1c269055a1ca8e8a5da399
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2396197


Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Kenichi Ishibashi <bashi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805607}