Using Google Assistant to make a call in an Android app

Question

I am trying to get Google system voice actions working in an Android app. Specifically using Google Assistant to initiate a call in an Android app. I can get an alarm to work with my app with no problem. Google assistant doesn't consider my app for making a call though. Is there anything different that needs to be done for a call vs an alarm for system voice actions?

To add support for alarms I added the following to the manifest:

<uses-permission android:name="com.android.alarm.permission.SET_ALARM"/>

<activity ...>
    <intent-filter>
        <action android:name="android.intent.action.SET_ALARM"/>
        <category android:name="android.intent.category.DEFAULT"/>
    </intent-filter>
</activity>

To add support for calls I added the following to the manifest:

<uses-permission android:name="android.permission.CALL_PHONE"/>

<activity ...>
    <intent-filter>
        <action android:name="android.intent.action.CALL"/>
        <category android:name="android.intent.category.DEFAULT"/>
    </intent-filter>
</activity>