Function Java_com_spruceid_DIDKit_issueCredential 

#[unsafe(no_mangle)]
pub extern "system" fn Java_com_spruceid_DIDKit_issueCredential(
    env: JNIEnv<'_>,
    _class: JClass<'_>,
    credential: JString<'_>,
    options: JString<'_>,
    key: JString<'_>,
) -> jstring