Add an indicator for AES GCM that returns if the iv has been generated

internally.

This is not using a strict check since there may be applications that
require the IV to be generated externally (e.g. java).

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/25178)