Change default assist app via intent

After downloading Cortana, it lets you set as the default device assist app. The app does that by firing up the specific settings page via intent. So, what is the specific intent for doing so? I have asked the same question to many forums, but I got the same answer- It is not possible... Turn out, it is.

Can anyone help me?

The intent code you are looking for is ACTION_VOICE_INPUT_SETTINGS. Here is the doc.

startActivityForResult(new Intent(android.provider.Settings. ACTION_VOICE_INPUT_SETTINGS), 0);