Avoid calculating the checksum on every snapshot deserialization.

- Desktop: by default only in release
- Android: once per process

Most snapshot corruptions happen on android devices but there we also
have the highest overhead from calculating the checksum.

Findings doc: https://docs.google.com/document/d/e/2PACX-1vQWdJjrZpTL5VjbP_LHH-qQj-9vcmuLez93WPZhoacJT2bTXfCAdJpbexfJWP9jrAI5ek_416uZE6_W/pub

Bug: v8:12195
Change-Id: Ic7f2f45a9e8ade31c3774a7b659d9c30769e2b44
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3583983Reviewed-by: Jakob Linke <jgruber@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#80260}