DatabaseNameUtil::parseTenantIdFromDatabaseName() tries to parse tenantID when gMultitenancySupport is disabled which is not very safe. We introduced that function for tenant migration as we night need to parse the tenantID even when gMultitenancySupport is disabled. In future, if parseTenantIdFromDatabaseName() is called outside of tenant migration code, we can cause bugs due to parsing tenantId w/ gMultitenancySupport disabled. To prevent this, we should move that function to tenant migration util file.