- The icon's `contentDescription` is used as the tooltip text.
- Tooltips are only shown for icons that are interactive (focusable). Decorative-only icons will not display a tooltip.
- `CheckableImageButton` is updated to provide a callback for when its focusable state changes, which is used to trigger tooltip updates.
- API-level differences are handled to ensure that custom `OnLongClickListeners` are not overridden by the tooltip's long-press listener on older platforms (pre-API 26).
PiperOrigin-RevId: 794951524