Previous behaviour : ProxyConfigs and Core are using the LinphoneAvpfMode enum which has 3 modes
*LinphoneAVPFDefault = -1, // Use default value defined at upper level
LinphoneAVPFDisabled
LinphoneAVPFEnabled*
However, in the LinphoneCallParams, the AVPF is only a boolean to represent Enabled/Disabled. And that boolean is not taken into account at all when using linphone_core_invite_with_params, as it is discarded in favor of the settings of the upper levels.
To try and match the user intent without bringing too many changes to the interface, we added another flag that will be set only when linphone_call_params_enable_avpf is called by the user. This way, we know that a specific behaviour is intended. If not, we default to the upper levels settings.