Add Speech Generation Metadata. (#1447)
Add Speech Generation Metadata. (#1447)


jdpedrie/google-cloud-php,googleapis/google-cloud-php,googleapis/google-cloud-php,chingor13/google-cloud-php,chingor13/google-cloud-php,jdpedrie/google-cloud-php,jdpedrie/google-cloud-php,googleapis/google-cloud-php,chingor13/google-cloud-php