Reinstate configs from disk across boots by fixing bugs

- Update configName to configID in StorageManager reflecting ag/3410772
- Fix a bug of using strtok destructivelyand correctly parse file name
- Fix a unit test to call StartupForTest of config manager

Bug: 70667694
Test: statsd, statsd_test
Change-Id: If32c02982d1f0c509bdd4e6f445924257bbc074b