feat(metastore): update the api

#### metastore:v1beta

The following keys were added:
- resources.projects.resources.locations.resources.services.resources.backups.methods.getIamPolicy (Total Keys: 14)
- resources.projects.resources.locations.resources.services.resources.backups.methods.setIamPolicy (Total Keys: 12)
- resources.projects.resources.locations.resources.services.resources.backups.methods.testIamPermissions (Total Keys: 12)

Author: yoshi-automation