Do not use ElementsAreArray for comparison

ElementsAreArray create an intermediate std::vector and that
causes a clang gc plugin to trigger. Use std::equal for
testing comparison of the two HeapVectors.

Bug: 1472371
Change-Id: I3e69624c694fb8c909e3dea95600a1f4cf7e046a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4789786


Reviewed-by: Jeremy Roman <jbroman@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1184839}