Add use_managed_db to relational db meta data
Add use_managed_db to relational db meta data

PiperOrigin-RevId: 322241128

GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker,GoogleCloudPlatform/PerfKitBenchmarker