Problem: cronos mainnet node is unable to export genesis

[yihuang]

Is your feature request related to a problem? Please describe. @JayT106 diagnosed that the main reason is max open files option of rocksdb is set too high, one solution is to lower that option so it can be finished within reasonable amount of ram.

Describe the solution you'd like

Make that option configuable.

Describe alternatives you've considered A clear and concise description of any alternative solutions or features you've considered.

Additional context Add any other context or screenshots about the feature request here.