* Create a LinphoneCallParams suitable for linphone_core_invite_with_params(), linphone_core_accept_call_with_params(), linphone_core_accept_early_media_with_params(),
* linphone_core_accept_call_update().
* The parameters are initialized according to the current LinphoneCore configuration and the current state of the LinphoneCall.
* @param lc the LinphoneCore
* @param call the call for which the parameters are to be build, or NULL in the case where the parameters are to be used for a new outgoing call.