Summary:
Added the Customizable::ConfigureNewObject method. The method will configure the object if options are found and invoke PrepareOptions if the flag is set properly.
Added tests to test that PrepareOptions is properly called and to test if PrepareOptions fails.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8468
Reviewed By: zhichao-cao
Differential Revision: D29494703
Pulled By: mrambacher
fbshipit-source-id: d5767dee5d7a98620ac66190262101cd0aa9d2b7