I am using this method to end a call in android
 public boolean killCall(Context context) {
    try {
        // Get the boring old TelephonyManager
        TelephonyManager telephonyManager =
                (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
        // Get the getITelephony() method
        Class classTelephony = Class.forName(telephonyManager.getClass().getName());
        Method methodGetITelephony = classTelephony.getDeclaredMethod("getITelephony");
        // Ignore that the method is supposed to be private
        methodGetITelephony.setAccessible(true);
        // Invoke getITelephony() to get the ITelephony interface
        Object telephonyInterface = methodGetITelephony.invoke(telephonyManager);
        // Get the endCall method from ITelephony
        Class telephonyInterfaceClass =
                Class.forName(telephonyInterface.getClass().getName());
        Method methodEndCall = telephonyInterfaceClass.getDeclaredMethod("endCall");
        // Invoke endCall()
        methodEndCall.invoke(telephonyInterface);
    } catch (Exception ex) { // Many things can go wrong with reflection calls
        Log.d(TAG, "PhoneStateReceiver **" + ex.getCause().getStackTrace());
        return false;
    }
    return true;
}
This does work before Oreo but does not working on android oreo any idea what is missing.
Best Regards: Ali
 
     
    