[native] Quick fix for EnumSettingsOption

Summary:
Sorry, forgot to (1) address the description length feedback and
(2) missed the ! operator for checking for an icon prop.

Test Plan:
Confirmed that the EnumSettingsOption works correctly with
the new description variable and with an icon

Reviewers: atul

Reviewed By: atul

Subscribers: ashoat, tomek

Differential Revision: https://phab.comm.dev/D8314