Summary:
**Context/Summary:**
https://github.com/facebook/rocksdb/pull/12567 disabled reopen with un-synced data loss in crash test since we discovered un-synced WAL loss and we currently don't support prefix recovery in reopen. This PR explicitly sync WAL data before close to avoid such data loss case from happening and add back the testing coverage.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/12746
Test Plan: CI
Reviewed By: ajkr
Differential Revision: D58326890
Pulled By: hx235
fbshipit-source-id: 0865f715e97c5948d7cb3aea62fe2a626cb6522a