Allow opening custom in-app call screen (self-managed) when tapping "Accept" on call notification

Is your proposal related to a problem?

I want to open my app’s custom call handling screen when the user taps the “Accept” button in the incoming call notification — in both Android and iOS. Currently, tapping “Accept” opens the system’s native call UI (from Android’s ConnectionService) instead of my app’s own call screen.

Describe the solution you'd like

Add an option to configure the package to open the custom call screen directly when the user taps “Accept”, regardless of whether the app is in foreground, background, or killed. The system’s Telecom UI should not appear at all.

Possible solutions:

Add a self-managed mode, for example:

CallKitConfig( selfManaged: true, onAcceptOpenApp: true, customCallActivity: 'com.example.app.CallActivity', );

Or, provide a callback:

CallKit.setOnAcceptListener((callId) { // Open in-app call screen Navigator.pushNamed(context, '/call', arguments: callId); });

Describe alternatives you've considered

Followed all setup steps from the package documentation.

Forked the repo and set Connection.PROPERTY_SELF_MANAGED in the ConnectionService, but the system call UI still appeared.

Tried handling the Accept action manually via a broadcast receiver, but it’s unreliable when the app is killed or in background.

Additional context

Flutter version: 3.35.3

Plugin version: 0.3.2+2

Android version: tested on Android 12, 13, 14 (Redmi and Pixel)

Goal: Achieve a consistent in-app call experience across both Android and iOS