Mark histogram V4LocalDatabaseManager.HasReceivedUpdateResponse as obsolete

This histogram has been stable historically and is no longer
needed.

Bug: 1167863
Change-Id: I1d42dd7c0a081f7c3a87e45dc8ad57eb49b73ed2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2727603


Reviewed-by: Daniel Rubery <drubery@chromium.org>
Reviewed-by: Ilya Sherman <isherman@chromium.org>
Commit-Queue: Ali Juma <ajuma@chromium.org>
Cr-Commit-Position: refs/heads/master@{#859780}