feat: enable regapic on remaining beta services (#6668)

feat(aiplatform/apiv1beta1): add REST transport

feat(artifactregistry/apiv1beta2): add REST transport

feat(bigquery/reservation/apiv1beta1): add REST transport

feat(billing/budgets/apiv1beta1): add REST transport

feat(datacatalog/apiv1beta1): add REST transport

feat(datalabeling/apiv1beta1): add REST transport

feat(dialogflow/apiv2beta1): add REST transport

feat(documentai/apiv1beta3): add REST transport

feat(gaming/apiv1beta): add REST transport

feat(gkeconnect/gateway/apiv1beta1): add REST transport

feat(mediatranslation/apiv1beta1): add REST transport

feat(metastore/apiv1alpha): add REST transport

feat(networkconnectivity/apiv1alpha1): add REST transport

feat(networksecurity/apiv1beta1): add REST transport

feat(notebooks/apiv1beta1): add REST transport

feat(recommendationengine/apiv1beta1): add REST transport

feat(retail/apiv2alpha): add REST transport

feat(retail/apiv2beta): add REST transport

feat(security/privateca/apiv1beta1): add REST transport

feat(security/publicca/apiv1beta1): add REST transport

feat(security/publicca/apiv1beta1/publiccapb): add REST transport

feat(securitycenter/apiv1beta1): add REST transport

feat(securitycenter/apiv1p1beta1): add REST transport

feat(securitycenter/settings/apiv1beta1): add REST transport

feat(videointelligence/apiv1p3beta1): add REST transport