Use deepcopy to create a backup from the arguments.

Passing arguments to a benchmark test should not be used in the next
test. The list is modified during the process. We need to load the
original list before running each Crossbench test.

Bug: 362607720
Change-Id: I1eef4a227bb1df44daece9c2e7203b37c1dcd66c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5833746
Reviewed-by: John Chen <johnchen@chromium.org>
Commit-Queue: Farid (Mojtaba) Faridzad <faridzad@google.com>
Cr-Commit-Position: refs/heads/main@{#1350598}