May override the global symbol_level config. Useful for debugging V8
within a release Chromium, like v8_enable_debugging_features.

Change-Id: Ie081b5110dc93914cbe53fdde3cdec77822b9819
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2051959
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66262}