Use base::test::EqualsProto

This is a pure code health clean-up CL for tests that roll their own
custom proto matcher. It removes those custom matchers and use the
equivalent one in base instead.

This CL was uploaded by git cl split.

R=kmackay@chromium.org

Change-Id: I40aab9e317fd604fe5819e3090bf6cc723225fa8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6470032
Auto-Submit: Jan Keitel <jkeitel@google.com>
Commit-Queue: Kenneth MacKay <kmackay@chromium.org>
Reviewed-by: Kenneth MacKay <kmackay@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1448368}