Add all unit tests into metrics_python_test.py

As crbug.com/40772738 is fixed by this chain of commits, the order of
the list of the test doesn't matter anymore.

This adds a lot of tests that were previously silently ignored (more
then half of all of the tests we have were not run).

For now the `jobs=1` is kept as it will require a couple extra fixes.

Bug: 482274154, 40772738
Change-Id: I94bf084ec5e8bb137efc3befa7c10521763de242
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/7558217
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Commit-Queue: Andrzej Fiedukowicz <afie@google.com>
Reviewed-by: Ramon Cano Aparicio <rcanoaparicio@google.com>
Cr-Commit-Position: refs/heads/main@{#1585209}