Follow-up changes might be required to fully fix up the contrib sandboxes.
PiperOrigin-RevId: 482475998
Change-Id: Iff631eb838a024b2f047a1be61bb27e35a8ff2f4
This change should make it less confusing where utility code comes from.
Having it in two places made sense when we were debating whether to publish
Sandbox2 separately, but not any longer.
Follow-up changes will move `sandbox2/util.h` and rename the remaining
`sandbox2/util` folder.
PiperOrigin-RevId: 351601640
Change-Id: I6256845261f610e590c25e2c59851cc51da2d778
