docs: update feature value docs (#5278)
docs: update feature value docs (#5278)

* Synchronize new proto/yaml changes.

PiperOrigin-RevId: 449052112

Source-Link: https://github.com/googleapis/googleapis/commit/3150afaab93bb09fc6331ea2665708b5cb30a4ec

Source-Link: https://github.com/googleapis/googleapis-gen/commit/9945a366e4a5efb00fc40985f03c107bdee89df2
Copy-Tag: eyJwIjoiQWlQbGF0Zm9ybS8uT3dsQm90LnlhbWwiLCJoIjoiOTk0NWEzNjZlNGE1ZWZiMDBmYzQwOTg1ZjAzYzEwN2JkZWU4OWRmMiJ9

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

Co-authored-by: Owl Bot <7f39581e9a7ddb69f3fa3e6fc69a582ea2916fc9@users.noreply.github.com>
googleapis/google-cloud-php,googleapis/google-cloud-php,googleapis/google-cloud-php