Change tools/trace_processor on release branch to match release

Not sure if this is intentional, but for every release branch, `tools/trace_processor` is one version behind the release version. For example, in `releases/v49.x`, `tools/trace_processor` is generated by v48.1.

It causes issues for vendored Perfetto - if we branch out from a release branch, the external trace processor could have a compatibility issue with Perfetto UI.

Am I using it wrong? Should we generate our own `trace_processor` script with the source code? What would be a better way to keep consistency between the external processor script and the Perfetto UI?