Bumps [libphonenumber](https://github.com/google/libphonenumber) from 8.12.18 to 8.12.19. - [Release notes](https://github.com/google/libphonenumber/releases) - [Changelog](https://github.com/google/libphonenumber/blob/master/making-metadata-changes.md) - [Commits](https://github.com/google/libphonenumber/compare/v8.12.18...v8.12.19) Signed-off-by: dependabot[bot] <support@github.com>