Bring back the ParsedQuicVersionIsValid DCHECK This DCHECK was originally added as part of cl/289536281 and subsequently removed in cl/289938397 to unbreak Chromium. This CL brings it back in a way that no longer breaks Chromium. Confirmed that this works in Chromium: https://chromium-review.googlesource.com/c/chromium/src/+/2008309 gfe-relnote: n/a, no behavior change apart from added DCHECK PiperOrigin-RevId: 290353213 Change-Id: Id22e311b4162706f44ad7436eefacb4cc286afdd